Open AccessProline Biosynthesis in Escherichia coli
Author(s) -
HAYZER David J.,
LEISINGER Thomas
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb05823.x
Subject(s) - escherichia coli , glutamate dehydrogenase , proline , enzyme , biochemistry , biosynthesis , dehydrogenase , chemistry , amino acid , biology , glutamate receptor , gene , receptor
Glutamate‐semialdehyde dehydrogenase, catalysing the reduction in vivo of γ‐glutamyl phosphate to glutamate 5‐semialdehyde in the pathway of proline biosynthesis in Escherichia coli , has been purified to homogeneity. High initial levels of the enzyme were achieved by using a multicopy ColEl‐ proA,B hybrid plasmid. The protein has a molecular weight of 1.89 × l0 5 and consists of four identical subunits of molecular weight 4.7 × l0 4 each. The pH optimum is 7.0 and the protein is stable for at least 10 min between pH 6.0−9.0 and for long periods at pH 7.0. It is rapidly inactivated at temperatures greatcr than 50°C. The enzyme is very sensitive to inhibition by p‐chloromercuribenzoate , copper and nickel ions.