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- Title
Phosphoglycolate Synthesis by Human Erythrocyte Pyruvate Kinase.
- Authors
Sasaki, Hiroko; Fujii, Shinya; Yoshizaki, Yoshiki; Nakashima, Koji; Kaneko, Toshio
- Abstract
R2-type pyruvate kinase purified monogeneously from human red cells catalyzes the phosphorylation of glycolate (glycolate kinase). Maximum activation of glycolate kinase was observed at 100 μMfructose-1,6-bisphosphate (Fru-1,6-P2) and at 2mM glucose-1,6-bisphosphate (Glc-1,6-P2). The Km for ATP was 1.1 mM in the absence of Fru-1,6-P2 and 1.5 mM in the presence of 1 mM Fru-1,6-P2. The Km for glycolate was 20 mMin the absence of Fru-1,6-P2 and 5 mM in the presence of 1.0 mM Fru-1,6-P2 The optimum pH was over 10.5. At the physiological concentrations of Fru-1,6-P2, Glc-162 and ATP, the glycolate kinase activity is too low to maintain the reported level of phosphoglycolate (approx. 2-5 μM). It is demonstrated that phosphoryltion of glycolate by R2-type pyruvate kinase which is predominant in mature red cells plays no physiological role. The questions whether an unknown pathway for phosphoglycolate synthesis exists or whether there is actually phosphoglycolate in red cells are raised. Copyright © 1987 S. Karger AG, Basel
- Publication
Acta Haematologica, 1987, Vol 77, Issue 2, p83
- ISSN
0001-5792
- Publication type
Article
- DOI
10.1159/000205959