Purification of GTP:alpha-D-mannose-1-phosphate guanyltransferase.
The enzyme GTP:alpha-D-mannose-1-phosphate guanylyltransferase from porcine thyroid tissue has been purified 69 900-fold on columns of blue-Sepharose, DEAE-Sepharose, phenyl-Sepharose and agarose-GTP affinity materials. Although it exhibits a tendency to aggregate, the enzyme travelled, upon sucrose velocity sedimentation, as a single oligomer with a molecular mass of 412 kDa. Michaelis constants were determined to be 1.0 microM, 1.0 mM, 3.5 microM and 0.4 microM for GDP-alpha-D-mannose, pyrophosphate, GTP and mannose-1-phosphate, respectively. The enzyme appears to be specific for the mannose moiety but will accept an inosine replacement for guanine and a deoxyribose replacement for ribose in GTP.
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D000818:Animals; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002621:Chemistry; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D004586:Electrophoresis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009713:Nucleotidyltransferases / Q000302:isolation & purification*; D013379:Substrate Specificity; D013552:Swine; D013961:Thyroid Gland / Q000201:enzymology*
D009713:Nucleotidyltransferases; C026917:mannose 1-phosphate guanylyltransferase