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. 1971 Dec;125(3):857–863. doi: 10.1042/bj1250857

The kinetic properties of human placental choline acetyltransferase

D Morris 1,*, A Maneckjee 1,†, Catherine Hebb 1
PMCID: PMC1178191  PMID: 5145909

Abstract

1. Michaelis constants for human placental choline acetyltransferase were shown to be dependent on the concentration of the second substrate present. The primary plots indicate a sequential rather than a Ping Pong mechanism and are of the same type with 300mm- and 500mm-sodium chloride. 2. Similar results have been obtained with rabbit brain choline acetyltransferase. 3. Product inhibition of the forward reaction has been studied. CoA inhibits competitively with respect to acetyl-CoA and non-competitively with respect to choline. Acetylcholine inhibits competitively with respect to choline and non-competitively with respect to acetyl-CoA. No inhibition is given by acetylcholine when the enzyme is saturated with choline. 4. It is concluded that human placental choline acetyltransferase has an ordered mechanism of the Theorell–Chance type.

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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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