Human liver GTP cyclohydrolase I: purification and some properties.
Human liver guanosine triphosphate (GTP) cyclohydrolase I has been purified more than 1,700-fold to what appears to be homogeneity. The active enzyme complex has an estimated molecular weight of 453,000 +/- 11,500 by gel filtration chromatography. It consists of a polypeptide of 149,000 +/- 4,000 mol wt by SDS-polyacrylamide gel electrophoresis. The activity of the enzyme is heat stable and is inhibited by di- and trivalent cations. The enzyme has an optimum pH of 7.7 in sodium phosphate buffer. It uses GTP as a sole substrate, with a Km of 116 microM.
Shen
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RS
Department of Human Biological Chemistry & Genetics, University of Texas Medical Branch, Galveston 77550.
Alam
A
A
Zhang
Y X
YX
D000619:Aminohydrolases / Q000302:isolation & purification*; D002499:Centrifugation, Density Gradient; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D006136:GTP Cyclohydrolase / Q000302:isolation & purification*; D006358:Hot Temperature; D006801:Humans; D008099:Liver / Q000201:enzymology*; D008970:Molecular Weight
D000619:Aminohydrolases; D006136:GTP Cyclohydrolase