Stereospecific production of the herbicide phosphinothricin (glufosinate): purification of aspartate transaminase from Bacillus stearothermophilus, cloning of the corresponding gene, aspC, and application in a coupled transaminase process.
نویسندگان
چکیده
We have isolated and characterized an aspartate transaminase (glutamate:oxalacetate transaminase, EC 2.6.1.1) from the thermophilic microorganism Bacillus stearothermophilus. The purified enzyme has a molecular mass of 40.5 kDa by sodium dodecyl sulfate gel analysis, a temperature optimum of 95 degrees C, and a pH optimum of 8.0. The corresponding gene, aspC, was cloned and overexpressed in Escherichia coli. The recombinant glutamate:oxalacetate transaminase protein was used in immobilized form together with 4-aminobutyrate:2-ketoglutarate transaminase (EC 2.6.1.19) from E. coli for the production of L-phosphinothricin [L-homoalanin-4-yl-(methyl)phosphinic acid], the active ingredient of the herbicide Basta (AgrEvo GmbH), from its nonchiral 2-keto acid precursor 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid (PPO). In this new coupled process conversion rates of ca. 85% were obtained with substrate solutions containing 10% PPO by using only slight excesses of the amino donors glutamate and aspartate. The contamination of the reaction broth with amino acid by-products was < 3%.
منابع مشابه
Stereospecific production of the herbicide phosphinothricin (glufosinate) by transamination: cloning, characterization, and overexpression of the gene encoding a phosphinothricin-specific transaminase from Escherichia coli.
We have cloned the gene encoding a 43-kilodalton transaminase from Escherichia coli K-12 with a specificity for L-phosphinothricin [L-homoalanine-4-yl-(methyl)phosphinic acid], the active ingredient of the herbicide Basta (Hoechst AG). The structural gene was isolated, together with its own promoter, and shown to be localized on a 1.6-kilobase DraI-BamHI fragment. The gene is subject to catabol...
متن کاملStereospecific production of the herbicide phosphinothricin (glufosinate) by transamination: isolation and characterization of a phosphinothricin-specific transaminase from Escherichia coli.
An aminotransferase capable of transaminating 2-oxo-4-[(hydroxy)(methyl)phosphinoyl]butyric acid to L-phosphinothricin [L-homoalanine-4-yl-(methyl)phosphinic acid], the active ingredient of the herbicide Basta (Hoechst AG), was purified to apparent homogeneity from Escherichia coli K-12. The enzyme catalyzes the transamination of L-phosphinothricin and various analogs with 2-ketoglutarate as th...
متن کاملThe Effect of Bialaphos on Ammonium-Assimilation and Photosynthesis I. Effect on the Enzymes of Ammonium-Assimilation
In this investigation, the effect of bialaphos (phosphinothricyl-alanyl-alanine) on the enzymes involved in NH4+-assimilation — glutamine synthetase, glutamine-2-oxoglutarate aminotrans ferase, glutamate dehydrogenase — is examined and compared to the effect of phosphinothricin (glufosinate) on the same enzymes. Bialaphos was given to whole plants (in vivo) and to leaf homogenate (in vitro). T...
متن کاملInfluence of calcium and non-phytate phosphorus deficient diets with phytase on the performance of broilers, serum concentrations of minerals and the activity of alanin transaminase, aspartate transaminase and lactate dehydrogenas e
متن کامل
Purification and characterization of an acidic, thermophilic phytase from a newly isolated Geobacillus stearothermophilus strain DM12
Microbial phytases were applied mainly to animal and human foodstuffs in order to improvemineral bioavailability and food processing. In addition, phytases have potentialbiotechnological application in various other fields, such as environmental protection,aquaculture and agriculture. Bacillus sp. DM12, an isolate from a hot spring, produces phytase,which catalyzes the hydrolysis of phytic acid...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Applied and environmental microbiology
دوره 62 10 شماره
صفحات -
تاریخ انتشار 1996