Ratio of hydantoinase and N-carbamoylase:key to preparation of D-amino acid from 5-monosubstituted hydantoin

IntroductionTheopticallyactiveD aminoacidsarevaluableintermediatesfortheproductionofsemi syntheticantibiotics;hormones ,bioactivepeptides ,and 5 monosubstitutedhydantoinsareimportantprecursorsforthecommercialproductionofaminoacids .Twoenzymesareinvolvedi…     

Burkholderic cepecia 1003产海因酶固定化条件

海因酶是利用海因酶法制备手性氨基酸的关键酶。采用Eupergit C、Eupergit C250 L及其氨基化后的载体作为固定化介质,对酶液pH值、蛋白浓度、固定化时间以及EDC用量等参数对海因酶固定化过程的影响进行研究,并在实验范围内,得到了上述参数的最优值。研究表明,环氧基载体的最适固定化条件为:酶液pH值为7.0,酶液蛋白质量浓度为0.4 mg/mL,固定化时间为20 h;氨基载体最适固定化条件为:酶液pH值为8.0,酶液蛋白质量浓度为0.4 mg/mL,固定化时间为10 h,EDC用量:Eupergit C(NH2)为70μL,Eupergit C250 L(NH2)为120μL。其中以Eupergit C250 L为固定化载体,海因酶的活性回收率可高达87%,且固定化酶的稳定性也较好,酶活半衰期长达2 500 h左右,具有较好的稳定性。     

Ratio of hydantoinase and N-carbamoylase: key to preparation of D-amino acid from 5-monosubstituted hydantoin

The optically active D-amino areas are valuable intermediates for the production of semi-synthetic antibiotics; hormones, bioactive peptides, and 5-monosubstituted hydantoins are important precursors for the commercial production of aminoacids. Two enzymes are involved in the stereo-selective deavage of D, L-S-monosubstituted hydantoins and N-carbamoyl amino acid (Fig. 1).