Biochemistry and biotechnology of mesophilic and thermophilic nitrile metabolizing enzymes

被引:65
作者
Cowan, D [1 ]
Cramp, R [1 ]
Pereira, R [1 ]
Graham, D [1 ]
Almatawah, Q [1 ]
机构
[1] Univ London Univ Coll, Dept Biochem & Mol Biol, London WC1E 6BT, England
关键词
mesophile; thermophile; nitrile hydratase; nitrilase; nitrile; thermostable; biotransformation;
D O I
10.1007/s007920050062
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Mesophilic nitrile-degrading enzymes are widely dispersed in the Bacteria and lower orders of the eukaryotic kingdom. Two distinct enzyme systems, a nitrilase catalyzing the direct conversion of nitriles to carboxylic acids and separate but cotranscribed nitrile hydratase and amidase activities, are now well known. Nitrile hydratases are metalloenzymes, incorporating Fe-III or Co-II ions in thiolate ligand networks where they function as Lewis acids. In comparison, nitrilases are thiol-enzymes and the two enzyme groups have little or no apparent sequence or structural homology. The hydratases typically exist as alpha beta dimers or tetramers in which the alpha- and beta-subunits are similar in size but otherwise unrelated. Nitrilases however, are usually found as homomultimers with as many as 16 subunits. Until recently, the two nitrile-degrading enzyme classes were clearly separated by functional differences, the nitrile hydratases being aliphatic substrate specific and lacking stereoselectivity, whereas the nitrilases are enantioselective and aromatic substrate specific. The recent discovery of novel enzymes in both classes (including thermophilic representatives) has blurred these functional distinctions. Purified mesophilic nitrile-degrading enzymes are typically thermolabile in buffered solution, rarely withstanding exposure to temperatures above 50 degrees C without rapid inactivation. However, operational thermostability is often increased by addition of aliphatic acids or by use of immobilized whole cells. Low molecular stability has frequently been cited as a reason for the limited industrial application of "nitrilases"; such statements notwithstanding, these enzymes have been successfully applied for more than a decade to the kiloton production of acrylamide and more recently to the smaller-scale production of nicotinic acid, R-(-)-mandelic acid and S-(+)-ibuprofen. There is also a rapidly growing catalog of other potentially useful conversions of complex nitriles in which the regioselectivity of the enzyme coupled with the ability to achieve high conversion efficiencies without detriment to other sensitive functionalities is a distinct process advantage.
引用
收藏
页码:207 / 216
页数:10
相关论文
共 70 条
[11]   CHARACTERIZATION OF NITRILE HYDRATASE GENES CLONED BY DNA SCREEING FROM RHODOCOCCUS-ERYTHROPOLIS [J].
DURAN, R ;
NISHIYAMA, M ;
HORINOUCHI, S ;
BEPPU, T .
BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 1993, 57 (08) :1323-1328
[12]   NITRILE HYDRATASE OF RHODOCOCCUS SP N-774 - PURIFICATION AND AMINO-ACID SEQUENCES [J].
ENDO, T ;
WATANABE, I .
FEBS LETTERS, 1989, 243 (01) :61-64
[13]   PRODUCTION OF S-(+)-2-PHENYLPROPIONIC ACID FROM (R,S)-2-PHENYLPROPIONITRILE BY THE COMBINATION OF NITRILE HYDRATASE AND STEREOSELECTIVE AMIDASE IN RHODOCOCCUS-EQUI TG328 [J].
GILLIGAN, T ;
YAMADA, H ;
NAGASAWA, T .
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY, 1993, 39 (06) :720-725
[14]  
GOLDLUST A, 1989, BIOTECHNOL APPL BIOC, V11, P581
[15]   CHARACTERIZATION OF A NITRILASE FROM NOCARDIA SP (RHODOCHROUS GROUP) NCIB 11215, USING PARA-HYDROXYBENZONITRILE AS SOLE CARBON SOURCE [J].
HARPER, DB .
INTERNATIONAL JOURNAL OF BIOCHEMISTRY, 1985, 17 (06) :677-683
[16]   FUNGAL DEGRADATION OF AROMATIC NITRILES - ENZYMOLOGY OF C-N CLEAVAGE BY FUSARIUM-SOLANI [J].
HARPER, DB .
BIOCHEMICAL JOURNAL, 1977, 167 (03) :685-692
[17]   MICROBIAL-METABOLISM OF AROMATIC NITRILES - ENZYMOLOGY OF C-N CLEAVAGE BY NOCARDIA SP (RHODOCHROUS-GROUP) NCIB 11216 [J].
HARPER, DB .
BIOCHEMICAL JOURNAL, 1977, 165 (02) :309-319
[18]   NITRILE HYDRATASE GENE FROM RHODOCOCCUS SP N-774 REQUIREMENT FOR ITS DOWNSTREAM REGION FOR EFFICIENT EXPRESSION [J].
HASHIMOTO, Y ;
NISHIYAMA, M ;
HORINOUCHI, S ;
BEPPU, T .
BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY, 1994, 58 (10) :1859-1865
[19]   LIGHT-INDUCED OXIDATION OF IRON ATOMS IN A PHOTOSENSITIVE NITRILE HYDRATASE [J].
HONDA, J ;
TERATANI, Y ;
KOBAYASHI, Y ;
NAGAMUNE, T ;
SASABE, H ;
HIRATA, A ;
AMBE, F ;
ENDO, I .
FEBS LETTERS, 1992, 301 (02) :177-180
[20]   Crystal structure of nitrile hydratase reveals a novel iron centre in a novel fold [J].
Huang, WJ ;
Jia, J ;
Cummings, J ;
Nelson, M ;
Schneider, G ;
Lindqvist, Y .
STRUCTURE, 1997, 5 (05) :691-699