scholarly journals Immobilization of a Novel ESTBAS Esterase from Bacillus altitudinis onto an Epoxy Resin: Characterization and Regioselective Synthesis of Chloramphenicol Palmitate

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 620 ◽  
Author(s):  
Fengying Dong ◽  
Xudong Tang ◽  
Xiaohui Yang ◽  
Lin Lin ◽  
Dannong He ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fourier Transform ◽  
Amino Acid ◽  
Epoxy Resin ◽  
Substrate Concentration ◽  
Hydroxyl Group ◽  
Optimum Temperature ◽  
Original Activity ◽  
Bacillus Altitudinis ◽  
Regioselective Modification

Novel gene estBAS from Bacillus altitudinis, encoding a 216-amino acid esterase (EstBAS) with a signal peptide (SP), was expressed in Escherichia coli. EstBASΔSP showed the highest activity toward p-nitrophenyl hexanoate at 50 °C and pH 8.0 and had a half-life (T1/2) of 6 h at 50 °C. EstBASΔSP was immobilized onto a novel epoxy resin (Lx-105s) with a high loading of 96 mg/g. Fourier transform infrared (FTIR) spectroscopy showed that EstBASΔSP was successfully immobilized onto Lx-105s. In addition, immobilization improved its enzymatic performance by widening the tolerable ranges of pH and temperature. The optimum temperature of immobilized EstBASΔSP (Lx-EstBASΔSP) was higher, 60 °C, and overall thermostability improved. T1/2 of Lx-EstBASΔSP and free EstBASΔSP at 60 °C was 105 and 28 min, respectively. Lx-EstBASΔSP was used as a biocatalyst to synthesize chloramphenicol palmitate by regioselective modification at the primary hydroxyl group. Conversion efficiency reached 94.7% at 0.15 M substrate concentration after 24 h. Lx-EstBASΔSP was stable and could be reused for seven cycles, after which it retained over 80% of the original activity.

scholarly journals Trigonopsis variabilis d-Amino Acid Oxidase: Control of Protein Quality and Opportunities for Biocatalysis through Production in Escherichia coli

2006 ◽  
Vol 73 (1) ◽  
pp. 331-333 ◽  
Author(s):  
Iskandar Dib ◽  
Damir Stanzer ◽  
Bernd Nidetzky
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Protein Quality ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Original Activity ◽  
Toxic Activity ◽  
Enzyme Preparations ◽  
Trigonopsis Variabilis ◽  
Natural Enzyme

ABSTRACT Trigonopsis variabilis d-amino acid oxidase accounts for 35% of Escherichia coli protein when added d-methionine suppresses the toxic activity of the recombinant product. Permeabilized E. coli cells are reusable and stabilized enzyme preparations. The purified oxidase lacks the microheterogeneity of the natural enzyme. Oriented immobilization of a chimeric oxidase maintains 80% of the original activity in microparticle-bound enzymes.

scholarly journals A New Resistance Gene, linB, Conferring Resistance to Lincosamides by Nucleotidylation in Enterococcus faecium HM1025

1999 ◽  
Vol 43 (4) ◽  
pp. 925-929 ◽  
Author(s):  
Bülent Bozdogan ◽  
Latifa Berrezouga ◽  
Ming-Shang Kuo ◽  
David A. Yurek ◽  
Kathleen A. Farley ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Amino Acid ◽  
Nucleotide Sequence ◽  
Amino Acid Sequence ◽  
Resistance Gene ◽  
Enterococcus Faecium ◽  
Hydroxyl Group ◽  
Significant Homology ◽  
Resistance Trait

ABSTRACT Resistance to lincomycin and clindamycin in the clinical isolateEnterococcus faecium HM1025 is due to a ribosomal methylase encoded by an ermAM-like gene and the plasmid-mediated inactivation of these antibiotics. We have cloned and determined the nucleotide sequence of the gene responsible for the inactivation of lincosamides, linB. This gene encodes a 267-amino-acid lincosamide nucleotidyltransferase. The enzyme catalyzes 3-(5′-adenylation) (the adenylation of the hydroxyl group in position 3 of the molecules) of lincomycin and clindamycin. Expression oflinB was observed in both Escherichia coli andStaphylococcus aureus. The deduced amino acid sequence of the enzyme did not display any significant homology with staphylococcal nucleotidyltransferases encoded by linA andlinA′ genes. Sequences homologous to linB were found in 14 other clinical isolates of E. faecium, indicating the spread of the resistance trait in this species.

scholarly journals Molecular Cloning and Characterization of Fengycin Synthetase Gene fenB from Bacillus subtilis

1998 ◽  
Vol 180 (5) ◽  
pp. 1338-1341 ◽  
Author(s):  
Guang-Huey Lin ◽  
Chyi-Liang Chen ◽  
Johannes Scheng-Ming Tschen ◽  
San-San Tsay ◽  
Yu-Sun Chang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Affinity Chromatography ◽  
Molecular Mass ◽  
Optimum Temperature ◽  
Turnover Number ◽  
Optimum Ph

ABSTRACT A fengycin synthetase gene, fenB, has been cloned and sequenced. The protein (FenB) encoded by this gene has a predicted molecular mass of 143.6 kDa. This protein was overexpressed inEscherichia coli and was purified to near homogeneity by affinity chromatography. Experimental results indicated that the recombinant FenB has a substrate specificity toward isoleucine with an optimum temperature of 25°C, an optimum pH of 4.5, aKm value of 922 μM, and a turnover number of 236 s−1. FenB also consists of a thioesterase domain, suggesting that this protein may be involved in the activation of the last amino acid of fengycin.

scholarly journals Amino acid substitutions and alteration in cation specificity in the melibiose carrier of Escherichia coli.

1988 ◽  
Vol 263 (28) ◽  
pp. 14276-14280 ◽  
Author(s):  
T Kawakami ◽  
Y Akizawa ◽  
T Ishikawa ◽  
T Shimamoto ◽  
M Tsuda ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Substitutions
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