Different half-lives of the carbohydrate and protein moieties of a 110,000-dalton glycoprotein isolated from plasma membranes of rat liver.

AUTOR(ES)

Kreisel, W

RESUMO

By using a four-step procedure (i, solubilization with Triton X-100; ii, affinity chromatography on concanavalin A-Sepharose; iii, affinity chromatography on wheat germ lectin-Sepharose; iv, preparative sodium dodecyl sulfate gel electrophoresis) a glycoprotein was isolated from rat liver plasma membrane. The molecular weight is 110,000 and the isoelectric point is 5.8. It contains L-fucose, N-acetylneuraminic acid, D-galactose, D-mannose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, and considerable quantities of aspartate, threonine, serine, and leucine. In pulse-chase experiments the half-lives of methionine and arginine, representing the half-life of the protein, were determined as 70 hr and 78 hr, respectively. The half-lives of the terminal carbohydrates L-fucose and N-acetylneuraminic acid were 12.5 and 33 hr, respectively. The galactose half-life was 20 hr. From this it is concluded that terminal sugars turn over several times in the life-span of this protein molecule. This process may be operative during membrane recycling mechanisms.

Documentos Relacionados

• Genetic control of the phenobarbital-induced shortening of plasma antipyrine half-lives in man
• Genetic control of the phenobarbital-induced shortening of plasma antipyrine half-lives in man
• Functional half-lives of bacteriophage m13 gene 5 and gene 8 messages.
• Forecasting cephalosporin and monobactam antibiotic half-lives in humans from data collected in laboratory animals.
• Purification of cowpea mosaic virus RNA replication complex: Identification of a virus-encoded 110,000-dalton polypeptide responsible for RNA chain elongation