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. 1966 Oct;101(1):70–75. doi: 10.1042/bj1010070

Kinetic studies with liver galactokinase

F J Ballard 1
PMCID: PMC1270067  PMID: 5971794

Abstract

1. Kinetic measurements of the forward reaction catalysed by ATP–galactose phosphotransferase were carried out with a purified preparation from pig liver. 2. The rate of reaction at pH7·8 is dependent on the concentration of MgATP2− rather than total ATP or magnesium chloride concentrations. 3. The effect of changes in pH on Km (galactose), Km (MgATP2−) and Vmax. was studied. 4. Of several possible nucleotide substrates only ATP and deoxyATP were effective. 5. The initial-velocity patterns both in the absence and presence of products were determined. 6. Galactose 1-phosphate is a non-competitive inhibitor when either galactose or MgATP2− was the variable substrate. 7. MgADP− was a non-competitive inhibitor with galactose and a competitive inhibitor with MgATP2− as variable substrate. 8. These results are consistent with an ordered reaction pathway in which galactose combines with an initial enzyme–MgATP2− complex.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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