|
type |
Journal Article |
authors |
Koide, Y.; Honma, M.; Shimomura, T. |
title |
L-Tryptophan-alpha-ketoisocaproate aminotransferase from Pseudomonas sp. |
journal |
Agric. Biol. Chem. |
Activity |
2.6.1.28 |
ui |
Taka |
year |
(1980) |
volume |
44 |
pages |
2013-2019 |
| |
abstract |
L-Tryptophan-a-ketoisocaproate aminotransferase (I) was purified from Pseudomonas species utilizing a-aminoisobutyrate. Purified I was homogeneous by polyacrylamide gel disc electrophoresis and ultracentrifugation. The mol. wt. was detd. to be 90,000 by sedimentation equil. and 110,000 by Sephadex G-150 gel filtration. The holoenzyme exhibited absorption max. at 330 and 415 nm. The addn. of L-leucine shifted the 415-nm peak to 330 nm. I showed a very broad substrate specificity, with high activity toward the branched-chain, straight-chain, and arom. amino acids and the corresponding a-keto acids, but it was not active with L-glutamate and a-ketoglutarate. The apparent Km values were as follows: L-leucine 0.4 mM, L-isoleucine 0.5 mM, L-valine 4.5 mM, L-phenylalanine 0.8 mM, L-tryptophan 1.4 mM, L-tyrosine 1.0 mM, a-ketoisocaproate 0.03 mM, a-ketoisovalerate 0.11 mM, and phenylpyruvate 0.08 mM.
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last changed |
2007/11/14 14:37 |
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