Rapid purification and characterization of human platelet glycoprotein V:
the amino acid sequence contains leucine-rich repetitive modules as in
glycoprotein Ib
T Shimomura, K Fujimura, S Maehama, M Takemoto, K Oda, T Fujimoto, R Oyama, M Suzuki, K Ichihara-Tanaka and K Titani
Department of Internal Medicine, Hiroshima University, Japan.
Glycoprotein V (GPV) is a membrane-associated, 82 Kd platelet glycoprotein
that is hydrolyzed during thrombin activation to yield 69 Kd fragment. We
have developed a rapid and simple method for isolation of the protein from
platelet extracts using a combination of gel permeation, anion-exchange,
and lectin affinity chromatography. The partial amino acid sequence was
determined by analysis of peptides generated by digestion of the
S-carboxyamido-methylated protein with Achromobacter protease I or cyanogen
bromide. The sequence shows a remarkable periodicity of leucine residues,
which is homologous to the consensus sequence of a highly diversified
protein super-family with a common repetitive module. Thrombin cleavage
site was determined to be located at the C-terminal region of GPV by
analysis of the products separated by sizing and reversed-phase high
performance liquid chromatography. By lectin blot analysis, the existence
of mucin-type carbohydrate chains was indicated, as well as the existence
of asparagine-linked carbohydrate chains shown by the amino acid sequence
analysis. From these data, we report a structural model of GPV that is
analogous to glycoprotein Ib.
Volume 75,
Issue 12,
pp. 2349-2356,
06/15/1990
Copyright © 1990 by The American Society of Hematology
