Biosynthèse des glycoprotéins dans le parenchyme pulmonaire. I. Activité mannosyl-transférase dans les fractions subcellulaires des pneumocytes
- 1 June 1973
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Biochemistry
- Vol. 51 (6) , 931-938
- https://doi.org/10.1139/o73-115
Abstract
An enzyme system exists in the membrane fraction of the alveolar cells of the lung, which catalyzes the transfer of mannose from guanosine diphosphate mannose (GDP-mannose) to an endogenous acceptor. The system is present in pellets that sediment at 10 000 g and 100 000 g. The optimal pH of the mannosyl transfer system is 5, and its optimal temperature is 27 °C. It is activated by Mn2+ and Mg2+ but is unaffected by Triton X 100, puromycin, and cycloheximide. The Michaelis constant for the substrate GDP-mannose is different for the enzyme sedimented by 10 000 g than for that by 100 000 g. Of a variety of nucleotides tested, only the guanosine nucleotides were effective as inhibitors of the activity of the two fractions.Keywords
This publication has 0 references indexed in Scilit: