Neuraminidases molecular weights

Figure 6. Variation of d with the molecular weight of dextrans (33), The data on Dx 20 (O) were obtained for neuraminidase-treated BBCs, and the results on larger dextrans were the same for normal and neuraminidase-treated cells. Vertical bars denote SEM.

Lll. LaMotta, R. V., Woronick, C. L., and Reinfrank, R. F., The molecular weights and isoelectric points of native and neuraminidase-treated human serum cholinesterase isoenzymes. Natl. Meet. Am. Chem. Soc., 160th, Chicago, Sept. 14-18 BIOL-185, (Abstr.) (1970). 

Eckersall, P. D., A. Thomas, G. M.Marshall, and T. A. Douglas. 1986. The effect of neuraminidase on the molecular weight aud the isoelectric poiut of the steroid iuduced alkafine phosphatase of dogs. Journal of Comparative Pathology 96 587-591. 

Storage of human saliva, serum, and duodenal secretion transformed the amylase fractions on cellulose acetate membrane electrophoresis into more-anionic forms. Incubation with lectins, proteases, D-glucosidases, neuraminidase, and some effectors did not modify this conversion, which was promoted by rising temperature and pH values. Increasing concentrations of ammonium ions delayed the transformation of amylolytic fractions, thus indicating non-enzymatic deamidation as the reason for amylase isoenzyme development. A change of molecular weight could be excluded. 

Investigations of the neuraminidase from Sendai virus have shown that it is a cell-surface glycoprotein (mol. wt. 1.4 x 10 ) composed of subunits of molecular weight 7.5 x lO (rather than of mol. wt. 5.3 x lO or 1.14 x 10 , as suggested by others). ... 

A number of glycoprotein receptors for wheat germ agglutinin have been isolated from rat synaptic membranes each can serve as a substrate for neuraminidase. However, an intrinsic neuraminidase present in the membranes selectively released neuraminic acid residues only from those glycoproteins having an apparent molecular weight > 7 x 10. ... 

Sialic acid was the first virus receptor identified. Hirst and McClelland and Hare discovered that influenza virus is able to hemagglutinate and that adsorbed virus is eluted from erythrocytes on incubation at 37°C, indicating an enzymatic destruction of a receptor substance on the cells [1, 2]. When a similar enzymatic activity was subsequently detected in Vibrio cholerae cultures, the term receptor-destroying enzyme was introduced [3]. The substance released by the viral enzyme from soluble hemagglutination inhibitors was initially characterized as a carbohydrate of low molecular weight [4] and then identified in crystalline form as A-acetyl-o-neuraminic acid [5]. Thus, it was clear that the receptor determinant of influenza virus was sialic acid and that the viral enzyme was a neuraminidase. Furthermore, for the first time an important biological function of sialic acid had been identified. 

The amoeba Acanthamoeba castellani has been shown to bind to equine erythrocytes by interaction with carbohydrates on the surface of the red cells. 4-Nitrophenyl tri-A-methyltyrosinate [ I]iodide has been used to label the outer surface of mature chicken erythrocytes. Two component glycoproteins, with subunits of molecular weight 5 x 10 and 1 x 10 , were identified. Neuraminidase-treated rat and rabbit erythrocytes were shown to be rapidly sequestered by the liver. Chemical studies of glycoproteins obtained from erythrocyte membranes from a number of sources have been reported. ... 

Certain strains of Streptomyces contain neuraminidases. The neuraminidases purified (1000-fold) from two such strains had similar molecular weights... 

The crystal structures of two representative small sialidases, with molecular weights around 40 kDa, have been determined one from Salmonella typhimurium [17] and one from Micromonospora viridifaciens [I8j. These reveal the same P-propeller fold seen in the influenza virus neuraminidase (Figure 2), despite having no sequence similarity to the viral enzyme, and not containing any disulphide bonds in contrast to the seven conserved disulfides in the viral enzyme. 

Beauregard, G., and Potier, M., 1982, Radiation inactivation of enzymes at low dose rates Identical molecular weights of rat liver cytosolic and lysosomal neuraminidases. Ana/. Biochem. 122 379-384. 

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