Background:Hydrolysis of 2-amino phenylpropionitrile by nitrilase is a fundamental biochemical reaction that produces chiral phenylalanine.For practical application of this biochemical reaction,researchers have attemp...Background:Hydrolysis of 2-amino phenylpropionitrile by nitrilase is a fundamental biochemical reaction that produces chiral phenylalanine.For practical application of this biochemical reaction,researchers have attempted to improve enzyme enantioselectivity and the reaction rate.Results:The substrate concentration was increased from 100 to 200 mM without substrate inhibition because of the formation of a substrate-hydroxypropyl-β-cyclodextrin(HP-β-CD)complex.Meanwhile,the activity of recombinant nitrilase increased 2.5 times because the addition of HP-β-CD solubilized hydrophobic substrates in the aqueous system.Furthermore,the formation of the substrate-HP-β-CD inclusion improved the enantioselectivity of the enzymatic reaction toward producing L-phenylalanine(L-Phe).The enantiomeric excess(e.e.)value of L-Phe increased from 65%to 83%when the conversion rate reached 50%.Conclusions:The recombinant nitrilase enantioselectively hydrolyzed 2-amino phenylpropionitrile to produce L-Phe.The addition of HP-β-CD to the reaction system enhanced the solubility and bioavailability of hydrophobic substrates as well as the enantioselectivity.The results showed that this additive has potential advantages in biochemical reactions of hydrophobic substrates,particularly for enantioselective biosynthesis.展开更多
Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The （R）-and （S）-2-n-butylbutanedioic ac...Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The （R）-and （S）-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with（S）-（ - ） or（R）-（ ＋ ）-α- methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with（R）-（ ＋ ）-α-methylbenzylamine and（S）- phenylalanine methyl ester.展开更多
文摘Background:Hydrolysis of 2-amino phenylpropionitrile by nitrilase is a fundamental biochemical reaction that produces chiral phenylalanine.For practical application of this biochemical reaction,researchers have attempted to improve enzyme enantioselectivity and the reaction rate.Results:The substrate concentration was increased from 100 to 200 mM without substrate inhibition because of the formation of a substrate-hydroxypropyl-β-cyclodextrin(HP-β-CD)complex.Meanwhile,the activity of recombinant nitrilase increased 2.5 times because the addition of HP-β-CD solubilized hydrophobic substrates in the aqueous system.Furthermore,the formation of the substrate-HP-β-CD inclusion improved the enantioselectivity of the enzymatic reaction toward producing L-phenylalanine(L-Phe).The enantiomeric excess(e.e.)value of L-Phe increased from 65%to 83%when the conversion rate reached 50%.Conclusions:The recombinant nitrilase enantioselectively hydrolyzed 2-amino phenylpropionitrile to produce L-Phe.The addition of HP-β-CD to the reaction system enhanced the solubility and bioavailability of hydrophobic substrates as well as the enantioselectivity.The results showed that this additive has potential advantages in biochemical reactions of hydrophobic substrates,particularly for enantioselective biosynthesis.
基金Supported by the National Basic Research Priority Program(No. 2003CCA027).
文摘Racemic 2-n-butylbutanedioic acid 4-t-butyl esters were synthesized from methyl hexanoate and t-butyl α-iodoacetate via alkylation and subsequently selective hydrolyzation. The （R）-and （S）-2-n-butylbutanedioic acid 4-t-butyl esters were obtained by the resolution of the above-mentioned racemic compounds with（S）-（ - ） or（R）-（ ＋ ）-α- methylbenzylamine, respectively. The e.e. values of the two optical active products were determined to be above 99% by HPLC after the formation of two pairs of diastereoisomers with（R）-（ ＋ ）-α-methylbenzylamine and（S）- phenylalanine methyl ester.
