Allergy information for: Abalone, perlemoen (Haliotis midae)

  • Name: Abalone, perlemoen
  • Scientific Name: Haliotis midae
  • Occurrence: Abalone is normally eaten as a cooked dish. It may be found in soups or Chinese dishes such as dim sum. It is sometimes used in rice porridge but this is not common as it is one of the most expensive shellfish.
  • Allergy Information:

    Allergy to shellfish such as abalone which are molluscs is less well known than allergy to shrimps (crustaceans). As with most food allergies, symptoms are usually mild such as oral allergy syndrome but severe symptoms such as anaphylactic shock can also occur after consumption. Note that abalone is not currently listed in annex IIIa of the EU directive on labelling of foods and thus individuals allergic to molluscs must be alert to the possibility of abalone or other molluscs as hidden allergens.

    Allergy to abalone is most commonly associated with allergy to other related shellfish such as limpet, snails, winkles and whelks (gastropods). Reactions can also be triggered by eating more distantly related molluscs such as clams, mussels, oysters, and scallops (bivalves) or cuttlefish, octopus and squid (cephalopods). Thus after a diagnosis of allergy to one mollusc, patients are normally advised to avoid all molluscs. Whilst most individuals with allergy to shrimps (crustacea) can tolerate molluscs, individuals with allergy to both types of shellfish have been reported. However, individuals allergic to finfish (such as cod or salmon) do not generally have allergies to shellfish.

    Supplementary information on Mollusc Allergy

    Molluscs1 include many of the most important seafoods such as abalone, clams, mussels, octopus, oysters, squid, and scallops as well as terrestrial snails. Marine molluscs and crustacea (shrimps, prawns, crabs, crayfish and lobsters) are both known as shellfish. There is a sharp legal distinction because annex IIIa of the new EU labelling directive makes the listing of crustaceans and crustacean products on labels mandatory but does not currently specify labelling molluscs. There is a clear biological difference between molluscs and crustacea but some limited cross-reactivity has been reported. Thus shrimp allergic individuals are more likely to react to molluscs than to an unrelated allergen such as a plant food.

    Biological classification
    To a zoologist, molluscs are a "phylum" on the same level as other phyla such as chordates (including sharks, bony fish and mammals) or arthropods (including insects, mites and crustacea). The most important divisions of the phylum mollusca are the classes bivalvia (bivalves such as clams, mussels, oysters, and scallops), cephalopoda (cephalopods such as cuttlefish, octopus and squid) and gastropoda (gastropods such as abalone, limpets, snails, winkles and whelks). However, members of other classes of molluscs such as chitons are also sometimes eaten although allergy to these has yet to be reported.

    Molluscs as Food
    Molluscs are eaten all over the world but the species eaten and the quantity consumed differs greatly from region to region. In many countries molluscs are eaten occasionally rather than as part of the staple diet.  Southern Europe, especially Spain, consumes more cephalopods as calamari and shellfish such as mussels than Northern Europe. The coastal regions of Asia are also major areas of mollusc consumption which are often included in Chinese dim sum, soup and rice porridge, making molluscs important hidden allergens in those dishes. More squid is consumed than any other seafood in Japan. Terrestrial snails are mostly eaten in France, Italy, Spain and Portugal.

    Symptoms of food allergy
    Adverse reactions following the ingestion of molluscs are similar to those reported for allergic reactions to other foods. They range from mild oral allergy syndrome (itching of the lips, mouth, or pharynx, and swelling of the lips, tongue, throat, and palate), through urticaria (hives), which is probably the most commonly reported symptom, to life-threatening systemic anaphylaxis (difficulty breathing, drop in blood pressure, and even death). Symptoms may involve the skin (itching, swelling), the gastro-intestinal tract (nausea and diarrhoea) and also respiratory symptoms (asthma, rhinitis). Most reported symptoms occurred within 90 minutes of ingesting the food. However, delayed reactions have been reported. The symptoms reported following the ingestion of molluscs may be unusual in two ways. Firstly, there may be a larger fraction of serious reactions than for most foods. Thus molluscs caused 5.6% and 11.7% of serious reactions in France in 2002 and 2003 and an article reported that 36% of cases of anaphylaxis at a clinic in Singapore were due to molluscs. A possible explanation could be that reactions might be attributed initially to bacterial contamination rather than food allergy so that consumption is continued.  Secondly, allergic reactions to snails very frequently involve asthma. This may be associated with allergy to dust mites which is involved in many cases of asthma and also in allergic reactions to snails.

    Symptoms generally occur after ingestion. However, symptoms have been reported on handling or inhaling steam from cooking molluscs and asthma has been associated with workers opening mussels. These reactions have been less frequently reported and less studied than similar occupational allergy to crustacea.

    Severe symptoms sometimes only occur when exercise follows shortly after eating molluscs (abalone or snails) as has also been reported for several other foods.

    Prevalence of food allergy to molluscs
    Studies based of questionnaires in the USA suggest that allergy to molluscs is less frequent than allergy to crustacea by a factor of approximately 3 but that a significant number of individuals suffer adverse reactions (>50 reacting to clam from 14,948 individuals). The frequency of food allergy probably follows the regional pattern of consumption, so that allergy to molluscs may be proportionally more important in France, Spain, Hong Kong or Singapore and less frequent in the United Kingdom or Germany.  Food allergies to molluscs have been reported in both children and adults and little is known about the persistence of allergy to molluscs.

    Cross reactions: how allergy to molluscs can result from or cause other allergies
    Our information on cross reactions is imperfect because oral challenge with molluscs has rarely been reported. Thus cross-reactions are identified from clinical histories, skin tests and tests for specific IgE from sera. In general for most food allergens negative skin prick tests predict the absence of allergy except for some food containing unstable allergens. However, some patients with positive skin tests do not react to oral challenges. Tests for specific IgE from sera produce both false positives and false negatives, especially if the patient is allergic to a biologically related organism such as, for example, the legumes peanut and soybean where it is found that many peanut allergic patients show IgE binding to soybean without clinical symptoms on eating soybean2.

    Cross-reactions are found between molluscs especially within the same class (bivalves, cephalopods or gastropods). For example, in a group of patients with a history suggesting shellfish allergy, patients with a positive skin test to clam had a 0.55 (55%) probability that they have a positive skin test to scallop, whereas those with a negative result with clam had only a 0.05 (5%) probability of a positive skin test to scallop. The same study found that those testing positive to abalone had only a 25% probability of a positive skin test to scallop but a 79% probability of a positive skin test to limpet. Thus those allergic to bivalves (clams, mussels, oysters, and scallops) are likely to react to other bivalves while those reacting to gastropods (abalone, limpets, snails, winkles and whelks) are likely to react to other gastropods. One case of fatal anaphylaxis on consumption of terrestrial snails has been reported of a patient who had been diagnosed as allergic to abalone showing that the cross reactions relate to biological families (gastropods) rather than to sea food versus land animals. However, cross-reactions between the classes of molluscs are also quite common.

    There is good evidence for cross reactions between molluscs and arthropods (the phylum contains insects, mites and crustacea) and two different cross-reactivities are reported. Allergy to crustacea (shrimps, lobster, crawfish, or crab) is generally due to allergy to a highly conserved muscle protein called tropomyosin. In vitro studies show that IgE antibodies (the class involved in allergy) from shrimp allergic patients also frequently bind to tropomyosins from molluscs. However, as noted above, this does not necessarily demonstrate clinical allergy. An alternative estimate come from the observation that a positive skin test with shrimp was associated with a 26%-41% probability of a positive skin test to scallop, clam, oyster, abalone or limpet. Tropomyosin is also involved in cross-reactions between insects and crustacea and it is possible that individuals with allergy to cockroaches and other arthropods might show cross-reactions with molluscs.

    The second well established cross-reaction is between dust mites and gastropods such as snails and limpets. This does not seem to depend on tropomyosin as only 2/28 patients in one study showed IgE binding to tropomyosin. In this case, the cross-reaction has been confirmed by oral challenges. For example, out of 51 children with dust mite allergy, 36 showed positive skin prick tests with snail. 15 of the children who had shown a positive skin test were challenged with cooked snails and 11 reacted. This suggests that as many as 30-40% of dust mite allergic individuals might react to snails although other studies have suggested that only approximately 15% might react. Allergy to limpet has also been associated with dust mite allergy. The reactions reported or observed were also unusual in that asthma was the most frequently reaction. Thus if you are dust mite allergic, have not recently eaten snails or related shellfish but intend to try them in future, it may be prudent to undergo a skin prick test to the relevant molluscs. The effects of desensitation therapy to dust mites on the probability and severity of reactions to molluscs has provoked controversy. This may be a topic to raise with your doctor if you are considering such therapy.

    No cross-reactions have been reported between molluscs and foods from fin fish, birds or mammals.

    Diagnostic procedures
    Allergies to molluscs are diagnosed using the same procedures as for other food allergies. A detailed patient history is first taken. Skin and laboratory tests are then used to identify the foods likely to cause allergic reactions, which can then be eliminated from the diet. Commercially available extracts from molluscs include abalone (Haliotis spp.), blue mussel (Mytilus edulis), clam (Ruditapes spp.), octopus (Octopus vulgaris), oyster (Ostrea edulis), pacific squid (Todarodes pacificus), scallop (Pecten spp.), snail (Helix aspersa) and squid (Loligo spp.). There are some pitfalls in investigating allergy to molluscs as the identification of the species eaten may not be simple, especially if a restaurant has substituted a cheaper mollusc such as limpet for an expensive one such as abalone.

    Skin prick testing appears to identify almost all cases of food allergy with some false positives. Skin prick test using fresh food often improves the identification of the suspected food. In vitro tests on sera are also helpful but there is insufficient data to assign probabilities of reaction to levels of specific IgE. Oral challenges have rarely been made with molluscs and the lowest threshold dosages remain to be elucidated.

    Dietary precautions
    Avoidance is the only therapy after diagnosis of an allergy to any mollusc. Because of the high probability of cross-reaction, it is probably sensible to eliminate from the diet all molluscs unless a negative skin test suggests that a species may be safely consumed. Even in that case, the difficulty of identifying molluscs after cooking suggests that care should be taken. Care should also be taken to avoid molluscs as ingredients in soups and dishes such as dim sum. Fortunately, there are no nutritional consequences to eliminating molluscs from the diet and no substitutes are required.

    1. "Mollusk" may be the preferred American spelling, and "mollusc" the British spelling but both date to the 1830s as translations of "mollusque" from Cuvier and both are used by American and British writers.

    2. It is believed that only high affinity IgE binding causes symptoms and that anti-peanut IgE binds weakly to related soybean proteins (the affinity is not measured by the standard tests).


  • Other Information:
  • Taxonomic Information: NEWT
  • Last modified: 18 October 2006

Reviews (0)

    References (0)

      Clinical History

      • Number of Studies:6-10
      • Number of Patients:>50
      • Symptoms:

        Thong et al. (2005) [1736] in a study of anaphylaxis in adults referred to a Singapore clinic found that ingestion of mollusks (abalone and limpet) was the most common cause of food related anaphylaxis with 11/30 cases.

        Lopata et al (1997) [1188] divided the symptoms of 38 patients with allergy to seafood into four categories: cutaneous, gastrointestinal, respiratory, and others. Respiratory reactions were more frequent in subjects who also had other atopic diseases. Although most of the subjects (66%) reported symptoms within 2 hours of food ingestion, a significant number of subjects (13; 34%) only reacted between 2 and 7 hours after eating. In both groups the majority of the subjects (76% and 69%, respectively) experienced cutaneous and respiratory symptoms, whereas the remaining subjects were first seen with gastrointestinal symptoms. Zinn et al (1997) [1299] described these patients together with additional fin fish and crustacea allergic patients. Reaction to abalone (also called perlemoen) was the third most common reaction to sea food after shrimps and crawfish with 38/105 patients reacting to abalone. Symptoms were not listed by food but it was noted that abalone caused several severe reactions.

        Maeda et al. (1991) [1696] report 11 patients who developed moderate to severe anaphylactic reactions following ingestion of grand keyhole limpet (GKL) and abalone. Some of these patients may also have been amongst those described by Morikawa et al. (1990) [1694] who reported 5 abalone allergic individuals. 2 of the individuals studied by Morikawa et al. (1990) only reacted 90 minutes to 3 hours after eating.

        Dohi et al (1991) [318] reported a single case of exercise induced anaphylaxis to abalone.

        One of the first cases of allergy to abalone was reported by Clarks (1979) [1737].

      Skin Prick Test

      • Number of Studies:1-5
      • Food/Type of allergen:

        Wu & Williams (2004) [1709] made abalone and limpet extracts by cold extraction of cooked shellfish in sterile PBS overnight. The extracts were centriguged at 50000 x g and the supernatants concentrated using Centricon YM-3 filter units (Millipore) to 20 mg/ml. Before use the extracts were sterile filtered and diluted 1:1 v/v with sterile glycerine.

        Lopata et al (1997) [1188] made five in-house extracts (abalone, oyster, black mussel, white mussel, and squid) diluted in 50% glycerol (vol/vol) and used one commercial blue mussel (Mytilus edulis) extract (Soluprick, ALK Laboratories, Horsholm, Denmark). Extracts were made from the edible portions which were cut into small pieces and tumbled overnight at 4° C in phosphate-buffered saline (PBS). After centrifugation at 1000 x g for 15 minutes, the extracts were sterilized by sterile filtration (0.45 µm; Millipore), and the protein content was determined by using a dye-binding method (BCA-protein assay, Pierce) and stored in aliquots (100 µl) at –20° C.

        Morikawa et al. (1990) [1694] minced grand keyhole limpet, abalone, carp and baby abalone-like shellfish and made 10% extracts in water for 48 hours. After centrifugation at 1000 x g for 30 minutes, the extracts were filtrated, lyophilised and stored at 4° C. Keyhole limpet haemocyanin was from Sigma (St Louise, USA). Skin tests used 490 µg/ml, 1.6 mg/ml and 380 µg/ml for grand keyhole limpet, keyhole limpet haemocyanin and abalone diluted in 50% v:v glycerol.

      • Protocol: (controls, definition of positive etc)

        Wu & Williams (2004) [1709] defined a positive SPT as 3 mm greater than the negative control.

        Lopata et al (1997) [1188] read SPTs after 15 minutes. These were considered to be positive if the diameter of the wheal was at least 3 mm greater than that produced by the negative control, saline and glycerol. Histamine dihydrochloride (10 mg/ml) was used as a positive control.

        Morikawa et al. (1990) [1694] read SPTs after 20 minutes. These were considered to be positive if the diameter of the wheal was at least 5 mm greater than that produced by the negative control of saline.

      • Number of Patients:

        Wu & Williams (2004) [1709] tested 84 patients who reported shellfish allergy.

        Lopata et al (1997) [1188] reported skin prick tests from 24 patients; 10 patients were excluded because they had reported very severe symptoms and 4 of the 38 seafood allergic patients identified were unable to attend.

        Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] report  skin prick tests on 11 and 5 patients respectively.

      • Summary of Results:

        Wu & Williams (2004) [1709] aimed to use SPT to diagnose to which shell fish their patients were allergic. They reported that 70 patients gave positive SPTs to a shellfish and that 45 patients were sensitised (i.e. SPT positive) to abalone and/or limpet. 27 of these were also sensitised to crustacea. Limpet gave more positive SPTs (40%) than abalone (26%).  

        Lopata et al (1997) [1188] report 14/24 positive SPTs for abalone, 9/24 for oyster, 10/24 for black mussel, 6/24 for blue mussel, 5/24 for white mussel and 7/24 for squid.  

        Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] report positive SPT in their patients to either abalone or grand keyhole limpet. 4/5 patients of Morikawa et al. (1990) reacted to grand keyhole limpet (1 of these had reacted after eating abalone) and 1/5 to abalone (the abalone positive child had reacted after eating grand keyhole limpet). Only 1/3 reacted to haemocyanin.

      IgE assay (by RAST, CAP etc)

      • Number of Studies:0
      • Food/Type of allergen:Lopata et al (1997) [1188] used extracts made as for SPT including an extract from snail, Helix aspersa.
      • IgE protocol:Lopata et al (1997) [1188], Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] used RAST. Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] also used RAST inhibition.
      • Number of Patients:

        Lopata et al (1997) [1188] tested sera from 38 patients who had reported symptoms with abalone and 10 fin fish sensitive controls.

        Maeda et al. (1991) [1696] and Morikawa et al. (1990) [1694] tested sera from 11 and 5 patients respectively.

      • Summary of Results:

        Lopata et al (1997) [1188] reported that 45% of all sera tested (17 of 38) gave an elevated RAST value (as % binding of IgE to abalone). Of the patients with positive RAST responses to abalone, 8 of 17 also had elevated IgE to snail. Individuals with negative SPT responses had little or no IgE reactivity to the abalone by RAST. 6 of the patients who had negative responses to RAST tests, had positive responses to SPTs (probably reflecting limitations of the RAST analysis).

        Maeda et al. (1991) [1696] reported a positive RAST for 11 patients. Morikawa et al. (1990) [1694] reported positive RAST for 5 patients with grand keyhole limpet and abalone.  Keyhole limpet hemocyanin and baby abalone-like extract was RAST positive with the 3 and 2 sera tested. RAST inhibition revealed cross antigenicity between grand keyhole limpet, abalone and keyhole limpet hemocyanin. Morikawa et al. (1990) reported that 1 sera was RAST positive for carp but that there was no RAST inhibition of the mollusc extracts with the carp extract.


      • Immunoblotting separation:Lopata et al (1997) [1188] separated proteins by SDS PAGE on 11% acrylamide 1D-separating gels by the method of Laemmli (1970) [948].
      • Immunoblotting detection method:Lopata et al (1997) [1188] electroblotted proteins onto polyvinylidene difluoride membrane (Hybond-PVDF, Amersham). Membranes were then cut into 5 mm strips, blocked for 30 minutes in 1% v/v blocking reagent (BM Chemiluminescence assay, Boehringer Mannheim), washed twice in PBS-Tween, and incubated overnight with 200 µl of serum sample in 3 ml of PBS. The strips were then washed twice with PBS-Tween for 10 minutes each and incubated for 2 hours with a mouse anti-human IgE antibody (diluted 1:3000 v/v in PBS). After washing twice, the strips were incubated for 30 minutes in biotinylated rabbit anti-mouse anti-serum (diluted 1:5000 v/v), washed, and finally incubated again in streptavidin-peroxidase (diluted 1:10,000 v/v) for another 30 minutes. After an overnight wash, the strips were developed by using a chemiluminescence detection system (Boehringer Mannheim) and exposed to Kodak x-ray film.
      • Immunoblotting results:Lopata et al (1997) [1188] reported that two IgE binding proteins with molecular weights of 49 and 38 kDa were consistently identified using sera from 5 of the 7 abalone allergic individuals tested. Higher molecular mass (50 - 70 kDa) allergens were also observed. IgE from the sera of abalone allergic patients also bound to proteins from snail, white mussel, black mussel, oyster, and squid. The main IgE binding protein from mussel had a molecular mass of 38 kDa and a protein from oyster at 38 kDa also bound IgE. High molecular mass allergens were also observed in snail and oyster extracts. Squid extract contained a 36 kDa protein which bound IgE strongly. Immunoblots with extracts from the abalone Haliotis rubra, with cooked H. midae or dried H. midae gave similar IgE binding patterns to those with extact of raw H. midae.

      Oral provocation

      • Number of Studies:0
      • Food used and oral provocation vehicle:
      • Blind:
      • Number of Patients:
      • Dose response:
      • Symptoms:No oral provocation reported.

      IgE cross-reactivity and Polysensitisation

      Lee & Park (2004) [1701] demonstrated strong IgE cross-reactivity between common whelk (Buccinum undatum) and abalone by ELISA inhibition.

      Wu & Williams (2004) [1709] report a case of a patient known to be allergic to abalone who suffered fatal anaphylaxis after eating 3 snails. They also found significant cross-reactivity between abalone and limpet based on SPT results. However, the "limpet" species was not well defined.

      Lopata et al (1997) [1188] show that the abalone species Haliotis midae and Haliotis rubra have similar allergens. They also show that IgE from abalone allergic individuals bound to proteins of other mollusks.

      Other Clinical information

      Lu et al. (2004) [1190] report a single monoclonal antibody against Japanese abalone (Haliotis discus) which distinguishes abalone from other mollusks. Lopata et al. (2002) [1735] report a system of  monoclonal antibodies capable of identifying the abalone species.

      Reviews (1)

      • Chu KH, Tang CY, Wu A, Leung PS.
        Seafood allergy: lessons from clinical symptoms, immunological mechanisms and molecular biology.
        Adv Biochem Eng Biotechnol. 97:205-235.. 2005
        PUBMEDID: 16261809

      References (13)

      • Lopata AL, Zinn C, Potter PC.
        Characteristics of hypersensitivity reactions and identification of a unique 49 kd IgE-binding protein (Hal-m-1) in abalone (Haliotis midae).
        J Allergy Clin Immunol. 100(5):642-648.. 1997
        PUBMEDID: 9389294
      • Morikawa A, Kato M, Tokuyama K, Kuroume T, Minoshima M, Iwata S.
        Anaphylaxis to grand keyhole limpet (abalone-like shellfish) and abalone.
        Ann Allergy 65(5):415-417.. 1990
        PUBMEDID: 2244714
      • Maeda S, Morikawa A, Kato M, Motegi Y, Shigeta M, Tokuyama K, Kuroume T, Naritomi Y, Suehiro K, Kusaba K, et al.
        [11 cases of anaphylaxis caused by grand keyhole limpet (abalone like shellfish)] Japanese.
        Arerugi 40(11):1415-1420.. 1991
        PUBMEDID: 1763963
      • Lee BJ, Park HS.
        Common whelk (Buccinum undatum) allergy: identification of IgE-binding components and effects of heating and digestive enzymes.
        J Korean Med Sci. 19(6):793-799.. 2004
        PUBMEDID: 15608387
      • Lu Y, Oshima T, Ushio H, Shiomi K.
        Preparation and characterization of monoclonal antibody against abalone allergen tropomyosin.
        Hybrid Hybridomics. 23(6):357-361.. 2005
        PUBMEDID: 15684662
      • Chu KH, Wong SH, Leung PS.
        Tropomyosin Is the Major Mollusk Allergen: Reverse Transcriptase Polymerase Chain Reaction, Expression and IgE Reactivity.
        Mar Biotechnol (NY). 2(5):499-509.. 2000
        PUBMEDID: 11246417
      • Lopata AL, Luijx T, Fenemore B, Sweijd NA, Cook PA.
        Development of a monoclonal antibody detection assay for species-specific identification of abalone.
        Mar Biotechnol (NY). 4(5):454-462.. 2002
        PUBMEDID: 14961238
      • Thong BY, Cheng YK, Leong KP, Tang CY, Chng HH.
        Anaphylaxis in adults referred to a clinical immunology/allergy centre in Singapore.
        Singapore Med J. 46(10):529-534.. 2005
        PUBMEDID: 16172772
      • Zinn C, Lopata A, Visser M, Potter PC.
        The spectrum of allergy to South African bony fish (Teleosti). Evaluation by double-blind, placebo-controlled challenge.
        S Afr Med J. 87(2):146-152.. 1997
        PUBMEDID: 9107219
      • Dohi M., Suko M., Sugiyama H., Yamashita N., Tadokoro K., Juji F., Okudaira H., Sano Y., Ito K. and Miyamoto T.
        Food-dependent, exercise-induced anaphylaxis: A study on 11 Japanese cases.
        J. Allergy Clin. Immunol 87: 34-40.. 1991
        PUBMEDID: 1991921
      • Clarks PS.
        Immediate respiratory hypersensitivity to abalone.
        Med J Aust. 1(13):623.. 1979
        PUBMEDID: 492019
      • Wu AY, Williams GA.
        Clinical characteristics and pattern of skin test reactivities in shellfish allergy patients in Hong Kong.
        Allergy Asthma Proc. 25(4):237-242.. 2004
        PUBMEDID: 15510583
      • Laemmli UK
        Cleavage of structural proteins during the assembly of the head of bacteriophage T4
        Nature 227:680-685. 1970
        PUBMEDID: 5432063

      Biochemical Information for Hal m 1

      • Allergen Name:Hal m 1
      • Alternatve Allergen Names:None
      • Allergen Designation:None
      • Protein Family:Not known
      • Sequence Known?:No
      • Allergen accession No.s:N/A
      • 3D Structure Accession No.:N/A
      • Calculated Masses:N/A
      • Experimental Masses:49 kDa
      • Oligomeric Masses:Not known
      • Allergen epitopes:Not known
      • Allergen stability:
        Process, chemical, enzymatic:

        IgE binding on immunoblots survives cooking.

      • Nature of main cross-reacting proteins:There are similar mass allergens in snail which bind IgE from abalone allergic patients.
      • Allergen properties & biological function:Not known
      • Allergen purification:Not reported.
      • Other biochemical information:Lopata et al (1997) [1188] identified the 49 kDa allergen from immunoblots using sera from 7 abalone allergic individuals but did not report additional molecular information.

      References (1)

      • Lopata AL, Zinn C, Potter PC.
        Characteristics of hypersensitivity reactions and identification of a unique 49 kd IgE-binding protein (Hal-m-1) in abalone (Haliotis midae).
        J Allergy Clin Immunol. 100(5):642-648.. 1997
        PUBMEDID: 9389294

      Biochemical Information for Tropomyosin

      • Allergen Name:Tropomyosin
      • Alternatve Allergen Names:The tropomyosin from Haliotis diversicolor has been unofficially named Hal d 1.
      • Allergen Designation:None
      • Protein Family:Pfam PF00261; Tropomyosin family
      • Sequence Known?:Sequence from Haliotis asinina, Haliotis diversicolor and Haliotis rufescens are available but only that from Haliotis diversicolor has been identified as an allergen.
      • Allergen accession No.s: (Haliotis diversicolor tropomyosin)

      • 3D Structure Accession No.:N/A
      • Calculated Masses:32823 Da
      • Experimental Masses:38 kDa
      • Oligomeric Masses:Tropomyosins form dimers.
      • Allergen epitopes:Not known
      • Allergen stability:
        Process, chemical, enzymatic:

        The allergenicity of tropomyosins can survive cooking, possibly because tropomyosin have a very simple helical structure which can rapidly refold after denaturation. Extracts from cooked abalone give similar immunoblots to extracts from raw abalone.

      • Nature of main cross-reacting proteins:

        The immunoblotting results of Lopata et al (1997) [1188] suggest that there is IgE cross-reactivity for tropomyosins between abalone and snail, white mussel, black mussel, oyster, and squid.

        More generally, Leung et al (1996) [1557] demonstrated cross-reactivity between tropomyosins from arthropods (crustacea and insects), tropomyosins from gastropods: abalone (Haliotis diveriscolor) and whelk (Hemifusus ternatana), bivalves: mussel (Perna viridis), pen shell (Pinna atropupurea), scallop, oyster (Crassostrea gigas) and clam (Lutraria philipinarum) and cephalopods: cuttlefish (Sepia madokai), squid (Loligo edulis) and octopus ((Octopus luteus).

        Chu et al (2000) [1189] also demonstrate IgE cross-reactivity by using recombinant tropomyosins from the abalone Haliotis diversicolor, the scallop Chlamys nobilis, and the mussel Perna viridis to inhibit IgE binding of shrimp allergic sera to shrimp extracts. 

      • Allergen properties & biological function:Tropomyosins bind to actin in muscle increasing thin filament stability and rigidity. Depolymerization from the pointed end is inhibited, without affecting elongation (Broschat, 1990 [1589]). As tropomyosin prevents the binding of myosin, it may play an important role with troponin in controlling muscle contraction. The sequence exhibits a prominent seven-residues periodicity and this is reflected in the interactions of the 2 polypeptide chains which form a coiled coil structure of two alpha-helices as originally proposed by Crick in 1952 (see the porcine structure 1C1G). Some tropomyosins are N-acetylated modifying the structure of the N terminal region and increasing the affinity for the thin filaments (Greenfield & Fowler, 2002 [1590]).
      • Allergen purification:

        Production of recombinant abalone, Haliotis diversicolor, tropomyosin as a fusion protein has been reported (Chu et al. 2000 [1189]).

      • Other biochemical information:

        The sequences of tropomyosins from abalone are rather similar to each other with sequences from Haliotis asinina Q7YZR4, Haliotis diversicolor Q9GZ71 and Haliotis rufescens Q25145 being 97-98% identical. A second sequence from Haliotis asinina Q7YZR3 is approximately 94% identical with these. The sequence from another gastropod, the snail Helix aspersa, O97192, is 86% identical. The bivalues show slightly lower levels of identity with oysters, scallops, mussels and clams having 70-80% sequence identity. Arthropod sequences are typically 57-63% identical and vertebrate sequences approximately 55% identical.

        Lu et al. (2004) [1190] report a single monoclonal antibody against Japanese abalone (Haliotis discus) tropomyosin which distinguishes abalone from other mollusks.

      References (7)

      • Lu Y, Oshima T, Ushio H, Shiomi K.
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