Characterization of a natural hemagglutinin in the serum of a freshwater crab Parathelphusa hydrodromus (Herbst).
A naturally occurring hemagglutinin (HA) was detected in the serum of the freshwater crab Parathelphusa hydrodromus using mammalian erythrocytes (RBC) as indicator cells. The serum gave the highest HA titer with rabbit RBC. In cross adsorption tests, this RBC type completely adsorbed all HA activities from serum. An analysis of the physico-chemical properties of HA showed it to be specifically dependent on the presence of Ca2+ for its activity, irreversibly sensitive to EDTA, stable between pH 7.5 and 10.0, and heat-labile. Further studies demonstrated that the HA is proteinaceous as it was precipitable by conventional deproteinizing agents, and susceptible to the action of proteases and 2-mercaptoethanol. HA-inhibition assays performed with 44 carbohydrates revealed that the serum HA was specific for non-reducing terminal glucose with alpha 1-2 glycosidic linkage. Thus this agglutinin appears to be unique among all the known crustacean agglutinins.
Department of Zoology, University of Madras, India.
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M
Nalini
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Mullainadhan
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M
Arumugam
D000327:Adsorption; D000818:Animals; D003386:Brachyura / Q000737:chemistry*; D002241:Carbohydrates / Q000097:blood*; D002413:Cations, Divalent; D055598:Chemical Phenomena; D011232:Chemical Precipitation; D002627:Chemistry, Physical; D004492:Edetic Acid; D004912:Erythrocytes / Q000378:metabolism*; D006388:Hemagglutinins / Q000097:blood*; D006863:Hydrogen-Ion Concentration; D013696:Temperature
D002241:Carbohydrates; D002413:Cations, Divalent; D006388:Hemagglutinins; D004492:Edetic Acid