Salmonidae protectins cross-react with human red cells having B, P, P(1) and P^k antigens, probably combining with an a-galactosyl-like determinant common to all these antigens. They have an apparent molecular weight of the order of 2 x 10^5 (S(20)w=8·9), which may explain the enhanced haemagglutinating activity in albumen displacement or enzyme tests. The saline anti-B activity for A(1)B cells rapidly deteriorated in storage. Cells previously suspended with albumin were no longer agglutinated by the protectins. It was only possible to obtain serologically active partially purified protectins from Sephadex G-200 gel filtration when normal human serum was added to the crude protectin reagent before applying to the gel. This may reflect lability of the tertiary structure of these proteins.
These studies indicate that α-galactose is the terminal and immunodominant sugar of the Pk determinant. Human anti-P^k and the ‘anti-P^k’ activity of salmon and trout protectins are strongly inhibited by α-galactosyl groups of galactose, disaccharides and macromolecules, e.g. P(1) substance. Removal of α-galactose from P(1) substance abolishes its ability to inhibit anti-P^k antibody activity. Anti-P^k antibody has a narrow spectrum for terminal α-galactosyl groups of cell surface antigens defining those of P^k but not those of B, P(1) or P(2) cells, while all these cells are agglutinated by the fish roe protectins. We suggest that anti-P^k antibody selects a larger determinant than the terminal α-galactosyl group and the full determinant is structurally different from those of B, P(1) and P(2) antigens. By contrast, fish roe agglutinins bind to a part only of the α-galactosyl group, present in all these antigens.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.