Mechanism of stereospecific conversion of DL-5-substituted hydantoins to the corresponding L-amino acids by Pseudomonas sp. strain NS671.
The mechanism of stereospecific conversion of DL-5-substituted hydantoins to the corresponding L-amino acids by Pseudomonas sp. strain NS671 was studied. The results indicated that the hydantoinase catalyzed the hydrolysis reaction of both D- and L-5-(2-methylthioethyl)hydantoin, and that the hydrolysis of the L-enantiomer proceeded preferentially compared with that of the D-enantiomer. On the basis of these findings, the mechanism was speculated to be as follows: DL-5-substituted hydantoins are converted exclusively to the L-forms of the corresponding N-carbamyl-amino acids by the hydantoinase in combination with hydantoin racemase. The N-carbamyl-L-amino acids are then converted to L-amino acids by N-carbamyl-L-amino acid amidohydrolase.
Ishikawa
T
T
Odawara Research Center, Nippon Soda Co., Ltd., Kanagawa, Japan.
Watabe
K
K
Mukohara
Y
Y
Nakamura
H
H
D000581:Amidohydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D006827:Hydantoins / Q000737:chemistry* / Q000378:metabolism*; D006868:Hydrolysis; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism*; D019998:Racemases and Epimerases / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013237:Stereoisomerism; D013379:Substrate Specificity; D013997:Time Factors
D000596:Amino Acids; D006827:Hydantoins; D011994:Recombinant Proteins; C072456:5-(2-methylthioethyl)hydantoin; D008715:Methionine; D000581:Amidohydrolases; C020047:dihydropyrimidinase; D019998:Racemases and Epimerases; C074773:hydantoin racemase