Biochemical characterization of a novel glucose isomerase from Anoxybacillus gonensis G2T that displays a high level of activity and thermal stability

2013 ◽  
Vol 97 ◽  
pp. 215-224 ◽  
Author(s):  
Hakan Karaoglu ◽  
Derya Yanmis ◽  
Fulya Ay Sal ◽  
Ayhan Celik ◽  
Sabriye Canakci ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Biochemical Characterization ◽  
Glucose Isomerase ◽  
Level Of Activity ◽  
High Level

scholarly journals Isolation and Biochemical Characterization of Two Novel Metagenome-Derived Esterases

2006 ◽  
Vol 72 (5) ◽  
pp. 3637-3645 ◽  
Author(s):  
C. Elend ◽  
C. Schmeisser ◽  
C. Leggewie ◽  
P. Babiak ◽  
J. D. Carballeira ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Biotechnological Applications ◽  
Temperature Optimum ◽  
Ph Optimum ◽  
Level Of Activity ◽  
Wide Range ◽  
Soil Metagenome ◽  
Ph Range ◽  
High Level

ABSTRACT The metagenomes of uncultured microbial communities are rich sources for novel biocatalysts. In this study, esterase EstA3 was derived from a drinking water metagenome, and esterase EstCE1 was derived from a soil metagenome. Both esterases are approximately 380 amino acids in size and show similarity to β-lactamases, indicating that they belong to family VIII of the lipases/esterases. EstA3 had a temperature optimum at 50�C and a pH optimum at pH 9.0. It was remarkably active and very stable in the presence of solvents and over a wide temperature and pH range. It is active in a multimeric form and displayed a high level of activity against a wide range of substrates including one secondary ester, 7-[3-octylcarboxy-(3-hydroxy-3-methyl-butyloxy)]-coumarin, which is normally unreactive. EstCE1 was active in the monomeric form and had a temperature optimum at 47�C and a pH optimum at pH 10. It exhibited the same level of stability as EstA3 over wide temperature and pH ranges and in the presence of dimethyl sulfoxide, isopropanol, and methanol. EstCE1 was highly enantioselective for (+)-menthylacetate. These enzymes display remarkable characteristics that cannot be related to the original environment from which they were derived. The high level of stability of these enzymes together with their unique substrate specificities make them highly useful for biotechnological applications.

scholarly journals The Severe Acute Respiratory Syndrome Coronavirus Nsp15 Protein Is an Endoribonuclease That Prefers Manganese as a Cofactor

2004 ◽  
Vol 78 (22) ◽  
pp. 12218-12224 ◽  
Author(s):  
Kanchan Bhardwaj ◽  
Linda Guarino ◽  
C. Cheng Kao
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Biochemical Characterization ◽  
Nonstructural Protein ◽  
Tryptophan Fluorescence ◽  
Conformation Change ◽  
Activity Concentrations ◽  
Level Of Activity ◽  
Novel Coronavirus ◽  
Endoribonuclease Activity

ABSTRACT Nonstructural protein 15 (Nsp15) of the severe acute respiratory syndrome coronavirus (SARS-CoV) produced in Escherichia coli has endoribonuclease activity that preferentially cleaved 5′ of uridylates of RNAs. Blocking either the 5′ or 3′ terminus did not affect cleavage. Double- and single-stranded RNAs were both substrates for Nsp15 but with different kinetics for cleavage. Mn2+ at 2 to 10 mM was needed for optimal endoribonuclease activity, but Mg2+ and several other divalent metals were capable of supporting only a low level of activity. Concentrations of Mn2+ needed for endoribonuclease activity induced significant conformation change(s) in the protein, as measured by changes in tryptophan fluorescence. A similar endoribonucleolytic activity was detected for the orthologous protein from another coronavirus, demonstrating that the endoribonuclease activity of Nsp15 may be common to coronaviruses. This work presents an initial biochemical characterization of a novel coronavirus endoribonuclease.

High-level expression and biochemical characterization of a novel cold-active lipase from Rhizomucor endophyticus

2016 ◽  
Vol 38 (12) ◽  
pp. 2127-2135 ◽  
Author(s):  
Xiaojie Duan ◽  
Mingming Zheng ◽  
Yu Liu ◽  
Zhengqiang Jiang ◽  
Shaoqing Yang
Keyword(s):  
Biochemical Characterization ◽  
High Level Expression ◽  
Cold Active ◽  
High Level ◽  
Active Lipase

scholarly journals Structural and biochemical characterization of mitochondrial citrate synthase 4 from Arabidopsis thaliana

2020 ◽  
Vol 76 (3) ◽  
pp. 109-115
Author(s):  
Kazuya Nishio ◽  
Tsunehiro Mizushima
Keyword(s):  
Arabidopsis Thaliana ◽  
Coenzyme A ◽  
Biochemical Characterization ◽  
Citrate Synthase ◽  
Tca Cycle ◽  
Folded Structure ◽  
The Tca Cycle ◽  
High Level ◽  
Inhibition Analysis

Citrate synthase (CS) catalyzes the conversion of oxaloacetate and acetyl coenzyme A into citrate and coenzyme A in the mitochondrial tricarboxylic acid (TCA) cycle. In plants, mitochondrial metabolism, including the TCA cycle, occurs in interaction with photosynthetic metabolism. The controlled regulation of several enzymes in the TCA cycle, such as CS, is important in plants. Here, the first crystal structure of a plant mitochondrial CS, CSY4 from Arabidopsis thaliana (AtCSY4), has been determined. Structural comparison of AtCSY4 with mitochondrial CSs revealed a high level of similarity. Inhibition analysis showed a similar manner of inhibition as in mitochondrial CSs. The effect of oxidation on one of a pair of cysteine residues in AtCSY4 was speculated upon based on the folded structure.

scholarly journals Identification and Characterization of Two Novel Clostridial Bacteriocins, Circularin A and Closticin 574

2003 ◽  
Vol 69 (3) ◽  
pp. 1589-1597 ◽  
Author(s):  
Robèr Kemperman ◽  
Anneke Kuipers ◽  
Harma Karsens ◽  
Arjen Nauta ◽  
Oscar Kuipers ◽  
...  
Keyword(s):  
Amino Acids ◽  
Indicator Strain ◽  
Clostridium Beijerinckii ◽  
Leader Peptide ◽  
Secretion Pathway ◽  
Level Of Activity ◽  
Clostridial Species ◽  
High Level ◽  
Identification And Characterization

ABSTRACT Two novel antibacterial peptides of clostridial species were purified, N-terminally sequenced, and characterized. Moreover, their structural genes were identified. Closticin 574 is an 82-amino-acid bacteriocin produced by Clostridium tyrobutyricum ADRIAT 932. The supernatant of the producing strain showed a high level of activity against the indicator strain C. tyrobutyricum. The protein is synthesized as a preproprotein that is possibly secreted via the general secretion pathway, after which it is hydrolyzed at an Asp-Pro site. Circularin A is produced by Clostridium beijerinckii ATCC 25752 as a prepeptide of 72 amino acids. Cleavage of the prepeptide between the third leucine and fourth valine residues followed by a head-to-tail ligation between the N and C termini creates a circular antimicrobial peptide of 69 amino acids. The unusually small circularin A leader peptide of three amino acids is cleaved off in this process. The supernatant of C. beijerinckii ATCC 25752 showed a broad antibacterial activity range.

scholarly journals PRODUÇÃO E CARACTERIZAÇÃO DE AMILASE DE Fusarium moniliforme E Aspergillus flavus

2000 ◽  
Vol 18 (1) ◽  
Author(s):  
EDSON LUIZ ZANGRANDO FIGUEIRA ◽  
MARCELA COLOGNESI DE SÁ ◽  
ELZA IOUKO IDA ◽  
ELISA YOKO HIROOKA
Keyword(s):  
Thermal Stability ◽  
Aspergillus Flavus ◽  
Fusarium Moniliforme ◽  
Biochemical Characterization ◽  
Storage Conditions ◽  
Maximum Activity ◽  
Amylase Production ◽  
Corn Kernels ◽  
Ground Corn

Considerando o interesse econômico da cultura do milho, alvo de ataque de fungos micotoxigênicos, esta investigação teve por objetivo a produção e caracterização bioquímica parcial de amilase das principais espécies problemáticas (Fusarium moniliforme e Aspergillus flavus). Empregandose cultivo em caldo de milho verde, adicionado de milho triturado, a maximização da produção de amilase de F. moniliforme e A. flavus ocorreu no 15o dia de fermentação. Submetendose o sobrenadante de cultura à precipitação fracionada com sulfato de amônio, entre 60 a 90% de saturação, obtevese a amilase fúngica, que foi caracterizada perante pH, temperatura e estabilidade térmica por metodologia de superfície de resposta. Em ambos os grupos fúngicos, a atividade enzimática foi maximizada em temperatura próxima a 40 °C, com pH em torno de 6,7 para amilase de F. moniliforme e 5,5 para A. flavus. A máxima estabilidade térmica da enzima de F. moniliforme ocorreu próximo a 21,0 °C. Abstract Regarding the economic relevance of corn culture and the fact that it can be a target to micotoxigenic fungi under improper storage conditions, this research aims the production of amylase and its partial biochemical characterization of the main problematic species Fusarium moniliforme and Aspergillus flavus. The fungi were cultivated in prepared medium containing both unripe and ground corn kernels. Maximum amylase production occurred on the 15th day of fermentation for both strains. The supernatant phase was fractionally precipitated with ammonium sulfate between 60 and 90% of saturation and the separated amylase had its parameters (pH, temperature and thermal stability) characterized by response surface methodology. Maximum activity was obtained at 40 °C and pH of 6.7 for the amylase of F. moniliforme and pH of 5.5 for the amylase of A. flavus. The optimal thermal stability for the enzyme of F. moniliforme occurred at 21 °C.

High level expression of a recombinant xylanase by Pichia pastoris cultured in a bioreactor with methanol as the sole carbon source: Purification and biochemical characterization of the enzyme

2016 ◽  
Vol 112 ◽  
pp. 161-169 ◽  
Author(s):  
Maribel Cayetano-Cruz ◽  
Ara Itzel Pérez de los Santos ◽  
Yolanda García-Huante ◽  
Alejandro Santiago-Hernández ◽  
Patricia Pavón-Orozco ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Carbon Source ◽  
Sole Carbon Source ◽  
Biochemical Characterization ◽  
High Level Expression ◽  
High Level
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