Production of optically active amino acids and their derivatives by microbial hydantoinase

(1)从土壤分离的恶臭假单胞菌胞内分离纯化并结晶了一种新的依赖于三磷酸腺苷的氨基水解酶(AIP-Hyantoinase)，该酶能催化多种5-取代的海因和三磷酸腺苷分别水解为N-氨基甲酰-L-氨基酸、氨和二氧化碳、二磷酸腺苷和无机磷。发现该酶不仅在有或没有酰胺底物的情况下都能催化几种核苷三磷酸的水解。动力学数据表明该酶在与酰胺底物结合后发生了构象变化。这种结合对于三磷酸核苷的水解似乎是绝对必要的。该酶可用于合成多种光学活性的N-氨基甲酰-L-氨基酸，并可用于血清或尿中肌酸的测定。(2)从一株革兰氏阴性菌中分离到一种对N-氨基甲酰-D-对羟基苯甘氨酸具有高度特异性的新的N-氨基甲酰-D-氨基水解酶，并对其进行了详细的鉴定。该酶具有较高的耐热性，可用于D-对羟基苯甘氨酸的实际生产。(3)从土壤中分离到一株恶臭假单胞菌SC-2，发现了一种能降解多种芳香族酰基的新型芳香族酰胺酶。在一株分离的土壤细菌中发现了一种新的酶，它能催化各种核苷氧化成相应的核苷5‘-羧酸，同时产生过氧化氢。该酶似乎与海因-嘧啶代谢密切相关。

(1)A novel ATP-dependent amidohydrolase(AIP-hydantoinase), which catalyzes hydrolysis of various 5-substituted hydantoins and ATP to the corresponding N-carbamoyl-L-amino acids, ammonia and carbon dioxide, and ADP and inorganic phosphate, respectively, was purified and crystallized from cells of a soil isolated bacterium PseudoMonas putida 77. the enzyme was found to catalyze the hydrolysis of several nucleoside triphosphates not only in the presence but also in the absence of amide substrate. The kinetic data suggested the conformational change of the enzyme after the binding of amide substrate. Such binding seemed to be absolutely necessary for the hydrolysis of nucleoside triphosphate. The enzyme was shown to be useful for the synthesis of various optically active N-carbamoyl-L-amino acids and for the determination of serum or urine creatine.(2)A new N-carbamoyl-D-amino acid amidohydrolase, which shows high specificity toward N-carbamoyl-D-p-hydroxyphenylglycine, was isolated from a Gram negative soil isolated bacterium and characterized in some details. The enzyme was shown to be highly thermostable and useful catalyst for the practical production of D-p-hydroxyphenylglycine.(3)A novel aromatic-aryl amidase which hydrolyzes various aromatic aryl-acyl amities, was found in a soil isolated Pseudomonase putida Sc-2. The enzyme was shown to be useful for optical resolution of various arcxuatic amines.(4)A new enzyme, nucleoside odidase which catalyzes oxidation of various nucleosides to the corresponding nucleoside 5'-carboxylic acids with concomitant production of hydrogenperoxide, was found in a soil isolated bacterium. The enzyme was seemed to have very close relation to the metabolism of hydantoin-pyrimidine metabolism.