Lectin-binding proteins in central-nervous-system myelin. Detection of glycoproteins of purified myelin on polyacrylamide gels by [3h]concanavalin A binding

Abstract

Concanavalin A strongly agglutinates purified fragments of immature and mature rat brain myelin, but only weakly agglutinates mature bovine and human myelin fragments. A sensitive method involving [3H]concanavalin binding to sodium dodecyl sulphate/polyacrylamide gels was used to detect the concanavalin A-binding proteins in purified myelin. When applied to mature rat brain myelin proteins that had been labelled in vivo with [14C]fucose, the distribution of the [3H]concanavalin A on the gel was very similar to that of [14C]fucose with the major peak corresponding to the major myelin-associated glycoprotein. The technique revealed that the immature form of the myelin-associated glycoprotein with a slightly larger apparent molecular weight also bound concanavalin A, and that in purified immature rat myelin the quantitative importance of some of the other glycoproteins in binding concanavalin A was increased relative to the myelin-associated glycoprotein. The separated proteins of bovine and human myelin bound more [3H]-concanavalin A than those of rat myelin. In these species, the myelin-associated glycoprotein was a major concanavalin A-binding protein, although two higher-molecular-weight glycoproteins also bound significant quantities of [3H]concanavalin A. The results indicate that there are receptors for concanavalin A on the surface of rat, bovine and human myelin membranes and suggest that the myelin-associated glycoprotein is one of the principal receptors.

Lectin-binding proteins in central-nervous-system myelin. Binding of glycoproteins in purified myelin to immobilized lectins

“…Doublelabelling experiments utilizing [3H]fucose-labelled glycoproteins from adult myelin and [14C]fucose-labelled glycoproteins from 14-day-old rat brain myelin did not reveal any difference in the binding of the mature and immature glycoproteins to any of the immobilized lectins. The results in this and the preceding paper [McIntyre, Quarles & Brady (1979) Biochem. J.…”

“…Binding of [3H]concanavalin A to myelin proteins after separation on sodium dodecyl sulphate/ polyacrylamide gels revealed several glycoproteins that bound concanavalin A. The major myelinassociated glycoprotein (Quarles et al, 1973a,b;Quarles, 1979) was one of the principal concanavalin A-binding proteins in each species (McIntyre et al, 1979). In the present paper, we report the results of experiments in which solubilized glycoproteins of purified myelin were bound to immobilized concanavalin A as a means of isolating the glycoproteins.…”

5′‐Nucleotidase in Rat Brain Myelin

“…A 5'-nucleotidase isolated from liver is a glycoprotein with a molecular weight of 140,000-150,000 (Evans and Gurd, 1973); 5'-nucleotidases isolated from brain have molecular weights of approximately 190,000 (Tanaka et al, 1973) and 140,000 (Ipata, 1968), and it has not, to our knowledge, been established whether they are glycoproteins. The effects of Con A and a-methyl-D-mannoside demonstrated here suggest that the myelin enzyme has D-mannose and/or D-glucose residues; future studies should determine whether 5'-nucleotidase accounts €or one of the many glycoproteins recently demonstrated in myelin by sensitive lectin-binding techniques (Mclntyre et al, 1979;Quarles et al, 1979;Poduslo et al, 1980).…”

Co-aggregation in Azospirillum brasilensense MTCC-125 with other PGPR strains: Effect of physical and chemical factors and stress endurance ability

“…The result of the present study is in conformity with the above findings and revealed the positive influence of EDTA in dispersing the Azospirillum co-aggregates and emphasized the role of outer membrane protein in co-aggregation. McIntyre et al (1979) after 24 h of incubation time. **In M 9 salts minimal media described by Sambrook et al (1989) with a slight modification from which PGPR cells are harvested at lag, log and stationary phase and utilized by co-aggregation assay.…”