Aspartic acid-484 of nascent placental alkaline phosphatase condenses with a phosphatidylinositol glycan to become the carboxyl terminus of the mature enzyme.

作者：Radmila Micanovic, Carole A. Bailey, Larry Brink, Louise Gerber, Y.-C. E. Pan, J D Hulmes, Sidney Udenfriend · 发表于：Proceedings of the National Academy of Sciences · 年份：1988 · DOI：10.1073/pnas.85.5.1398 · 被引用次数：97 · 研究领域：Alkaline Phosphatase Research Studies、Biochemical and Molecular Research、Folate and B Vitamins Research

A carboxyl-terminal chymotryptic peptide from mature human placental alkaline phosphatase was purified by HPLC and monitored by a specific RIA. Sequencing and amino acid assay showed that the carboxyl terminus of the peptide was aspartic acid, representing residue 484 of the proenzyme as deduced from the corresponding cDNA. Further analysis of the peptide showed it to be a peptidoglycan containing one residue of ethanolamine, one residue of glucosamine, and two residues of neutral hexose. The inositol glycan is apparently linked to the alpha carboxyl group of the aspartic acid through the ethanolamine. Location of the inositol glycan on Asp-484 of the proenzyme indicates that a 29-residue peptide is cleaved from the nascent protein during the post-translational condensation with the phosphatidylinositol-glycan.