CAJ | 학술논문

将类球红杆菌(Rhodobacter sphaeroides)全细胞及其分离得到的羰基还原酶用于不对称催化还原多种潜手性酮类化合物,通过比较产物的收率、ee值、酶活力以及酶学动力学常数K_m,探讨了类球红杆菌的催化还原性质与底物结构的关系.结果表明,对于类球红杆菌全细胞不对称催化还原苯乙酮衍生物,产物ee值的变化遵循Prelg规则,产物收率与底物苯环及侧链上取代基团的性质有关;对于脂肪酮催化还原,产物收率随底物链长的增加和分子量的增大而降低,随支链数日的增加而升高,产物ee值的变化也遵循Prelg规则.利用羰基还原酶不对称催化还原潜手性酮类化合物发现,对于芳香酮类化合物,酶对α位为强电负性基团的底物专一性较强;对于脂肪酮类化合物,酶对五碳脂肪酮的专一性较高.利用酶直接催化还原反应产物的ee值均为99%左右,表明酶较全细胞有更高的立体选择性.
장류구홍간균(Rhodobacter sphaeroides)전세포급기분리득도적탄기환원매용우불대칭최화환원다충잠수성동류화합물,통과비교산물적수솔、ee치、매활력이급매학동역학상수K_m,탐토료류구홍간균적최화환원성질여저물결구적관계.결과표명,대우류구홍간균전세포불대칭최화환원분을동연생물,산물ee치적변화준순Prelg규칙,산물수솔여저물분배급측련상취대기단적성질유관;대우지방동최화환원,산물수솔수저물련장적증가화분자량적증대이강저,수지련수일적증가이승고,산물ee치적변화야준순Prelg규칙.이용탄기환원매불대칭최화환원잠수성동류화합물발현,대우방향동류화합물,매대α위위강전부성기단적저물전일성교강;대우지방동류화합물,매대오탄지방동적전일성교고.이용매직접최화환원반응산물적ee치균위99%좌우,표명매교전세포유경고적입체선택성.
The asymmetric reduction of ketones catalyzed by whole cells or carbonyl reductase ofRhodobacter sphaeroides was studied. The relationship between catalytic ability of Rhodobacter sphaeroides and the structure of substrates was determined by evaluating the yields, ee value, enzyme activity, and kinetic constant (K_m value) of enzyme. The ee value followed the Prelg rule. The yield was related to the substitution on the benzene ring and side-chain of acetophenone derivatives. The yield decreased with increasing length of the chain and molecular mass of the substrates but was enhanced with the increase of the number of branched-chains for aliphatic ketones. The results of asymmetric reduction of latent chiral ketones by carbonyl reductase showed that the enzyme had a high specificity for pentanone in aliphatic ketones and for the acetophenone derivates that contained a withdrawing group at α-position. In the enzyme-catalyzed asymmetric hydrogenation, all the product ee values were around 99%, indicating that the carbonyl reductase had higher stereoselectivity than the whole cells.