|
type |
Journal Article |
authors |
Cooper, J. L.; Meister, A. |
title |
Isolation and properties of highly purified glutamine transaminase |
journal |
Biochemistry |
Activity |
2.6.1.15 |
sel |
selected |
ui |
5059882 |
year |
(1972) |
volume |
11 |
number |
5 |
pages |
661-71 |
| |
keywords |
Amino Acids |
abstract |
Glutamine transaminase has been obtained in highly purified form from rat liver. The isolated enzyme, which is apparently homogeneous by the criteria of ultracentrifugation S20,w= 6.25 S) and polyacrylamide gel electrophoresis, has a molecular weight of about 110,000. The enzyme exhibits absorbance maxima at 278 and 415 nm and the data indicate that the enzyme contains two subunits (mol wt -54,000). The enzyme is stabilized by a-keto acids and by 2-mercaptoethanol. Studies with 27 alpha-keto acids and 40 amino acids indicate that a-ketoglutaramate, a-keto-y-methiolbutyrate,
P-mercaptopyruvate, glyoxylate, pyruvate, and Phydroxypyruvate are among the most active a-keto acid substrates, and that glutamine, glutamic acid gamma-ethyl ester, gamma-glutamylmethylamide, methionine, and ethionine are among the most active amino donors. The K, values for a number of the a-keto acids and amino acids, and the equilibrium constants for the glutamine-pyruvate, -glyoxylate, -alpha-keto-gamma-methiolbutyrate reactions were determined. |
last changed |
2009/04/28 09:53 |
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