Biochemical characterization of thermostable ω-transaminase from Sphaerobacter thermophilus and its application for producing aromatic β- and γ-amino acids

2016 ◽  
Vol 87-88 ◽  
pp. 52-60 ◽  
Author(s):  
Sam Mathew ◽  
Saravanan Prabhu Nadarajan ◽  
Taeowan Chung ◽  
Hyun Ho Park ◽  
Hyungdon Yun
Keyword(s):  
Amino Acids ◽  
Biochemical Characterization

scholarly journals Phenotypic, Genetic and Biochemical Characterization of Five Tunisian Varieties of Chickpea

2017 ◽  
Vol 5 (1) ◽  
pp. 77 ◽  
Author(s):  
Mongi Melki ◽  
Abir Gsouri ◽  
Mariem Bouhadida ◽  
Hnya Chograni ◽  
Mohsen Rezgui
Keyword(s):  
Amino Acids ◽  
Biochemical Characterization ◽  
Block Design ◽  
Field Trials ◽  
Morphological Characters ◽  
Yield Potential ◽  
Polymorphism Analysis ◽  
Sulfur Amino Acids ◽  
Semi Arid Region

Five Tunisian varieties of Kabuli chickpea were characterized based on agro morphological, molecular and biochemical parameters to investigate their genetic variability and yield potential. Randomized complete block design field trials were carried out in the upper semi-arid region of Kef in Tunisia during the 2013-2014 seasons. Data analysis showed significant differences between genotypes for several parameters. The results indicated that these genotypes could be set into two different groups. The first group composed of Bochra and Chetoui genotypes. Kasseb, Neyer and Beja1 were in the second group. Genotypes in each group were closely related to each other according to their common morphological characters such as pod number, one hundred seeds weight and yield.  Chetoui and Kasseb varieties are later in comparison to other varieties. Genetic diversity was studied using simple sequence repeat (SSR) markers. Four loci (TA64, TA71, TA96, TA194) were multiallelic. Whereas while two loci (TA72, GAA47) were monomorphic. Polymorphism analysis showed a phylogeny related to genotypes differentiation according to their relatives, origin and several morphological characters. Bochra variety had high amino acids content followed by Chetoui variety. All the varieties were deficient in sulfur amino acids. Chickpeas protein contents were variable and high ranging from 18% to 25%.

Biochemical Characterization of Branched Chain Amino Acids Uptake in Trypanosoma cruzi

2015 ◽  
Vol 63 (3) ◽  
pp. 299-308 ◽  
Author(s):  
Nubia C. Manchola ◽  
Ludmila N. Rapado ◽  
María J. Barisón ◽  
Ariel M. Silber
Keyword(s):  
Amino Acids ◽  
Trypanosoma Cruzi ◽  
Biochemical Characterization ◽  
Branched Chain Amino Acids ◽  
Branched Chain

Growth and biochemical characterization of associations between cyanobionts and wheat seedlings in co-culturing experiments

Biologia ◽  
2011 ◽  
Vol 66 (1) ◽  
Author(s):  
Anjuli Sood ◽  
Pawan Singh ◽  
Arun Kumar ◽  
Rajendra Singh ◽  
Radha Prasanna
Keyword(s):  
Amino Acids ◽  
Indoleacetic Acid ◽  
Biochemical Characterization ◽  
Shoot Biomass ◽  
Wheat Seedlings ◽  
Symbiotic Associations ◽  
Plant Groups ◽  
Wide Range ◽  
Root And Shoot Biomass

AbstractN2-fixing cyanobacteria are unique in their capacity to form symbiotic associations with a wide range of eukaryotic hosts belonging to different plant groups. The present study was undertaken to analyze the interactions of the cyanobiont PI 01 (from Azolla pinnata) and Nostoc PCC 9229 (from Gunnera monoika) with wheat seedlings, in co-culturing experiments. Each of the cyanobionts enhanced significantly the volume of root and shoot biomass in the experimental cultures. The transverse sections of roots in the co-cultured seedlings revealed the presence of aseriate packets of cyanobionts below the root epidermis. The investigated cyanobionts excreted amino acids (His, Met, Val) and sugars into the medium, while indoleacetic acid was detected when the cyanobionts were grown in a tryptophan containing medium. During the co-culturing, sugars and proline were detected in the extracellular filtrates. It can be hypothesized that these sugars and amino acids may serve as signal substances in the development of functional associations between the relevant cyanobionts and the wheat seedlings.

scholarly journals Genetic and Biochemical Characterization of OXA-535, a Distantly Related OXA-48-Like β-Lactamase

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
L. Dabos ◽  
A. B. Jousset ◽  
R. A. Bonnin ◽  
N. Fortineau ◽  
A. Zavala ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequence Identity ◽  
Biochemical Characterization ◽  
Content Type ◽  
Sequence Identity

ABSTRACT OXA-535 is a chromosome-encoded carbapenemase of Shewanella bicestrii JAB-1 that shares only 91.3% amino acid sequence identity with OXA-48. Catalytic efficiencies are similar to those of OXA-48 for most β-lactams, except for ertapenem, where a 2,000-fold-higher efficiency was observed with OXA-535. OXA-535 and OXA-436, a plasmid-encoded variant of OXA-535 differing by three amino acids, form a novel cluster of distantly related OXA-48-like carbapenemases. Comparison of blaOXA-535 and blaOXA-436 genetic environments suggests that an ISCR1 may be responsible for blaOXA-436 gene mobilization from the chromosome of Shewanella spp. to plasmids.

Discovery and Biocatalytic Application of a PLP-Dependent Amino Acid γ-Substitution Enzyme that Catalyzes C-C Bond Formation

2020 ◽  
Author(s):  
Mengbin Chen ◽  
Chun-Ting Liu ◽  
Yi Tang
Keyword(s):  
Amino Acids ◽  
Biosynthetic Pathway ◽  
Pyridoxal Phosphate ◽  
Biochemical Characterization ◽  
Indole Alkaloid ◽  
Building Blocks ◽  
Nucleophilic Attack ◽  
Keto Esters ◽  
Key Enzyme

Pyridoxal phosphate (PLP)-dependent enzymes can catalyze various transformations of amino acids at alpha, beta, and gamma positions. These versatile enzymes are prominently involved in the biosynthesis of nonproteinogenic amino acids as building blocks of natural products, and are attractive biocatalysts. Here, we report the discovery of a two-step enzymatic synthesis of (2<i>S, </i>6<i>S</i>)-6-methyl pipecolate <b>1</b>, from the biosynthetic pathway of indole alkaloid citrinadin. The key enzyme CndF is PLP-dependent and catalyzes synthesis of (<i>S</i>)-2-amino-6-oxoheptanoate <b>3</b> that is in equilibrium with the cyclic Schiff base. The second enzyme CndE is a stereoselective imine reductase that gives <b>1</b>. Biochemical characterization of CndF showed this enzyme performs gamma-elimination of <i>O</i>-acetyl L-homoserine to generate the vinylglycine ketimine, which is subjected to nucleophilic attack by acetoacetate to form the new C<sub>gamma</sub>-C<sub>delta</sub> bond in <b>3 </b>and complete the gamma-substitution reaction. CndF displays substrate promiscuity towards different beta-keto carboxylate and esters. Using a recombinant <i>Aspergillus </i>strain expressing CndF and CndE, feeding various alkyl-beta-keto esters led to the biosynthesis of 6-substituted L-pipecolates. The discovery of CndF expands the repertoire of reactions that can be catalyzed by PLP-dependent enzymes.

scholarly journals Isolation and preliminary biochemical characterization of the gonococcal H.8 antigen.

1986 ◽  
Vol 164 (6) ◽  
pp. 2038-2048 ◽  
Author(s):  
W Strittmatter ◽  
P J Hitchcock
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Preliminary Analysis ◽  
Chemical Nature ◽  
Biochemical Characterization ◽  
Sulfur Containing ◽  
Lipid Components

We have presented a method for the extraction and isolation of the gonococcal H.8 antigen. There was no evidence of contamination by other gonococcal proteins, phospholipids, or LPS. The purified H.8 antigen was subjected to preliminary analysis and appeared to be a proteolipid consisting of both protein and lipid components. The amino acid composition was unusual; the peptide portion of the antigen was an alanine and proline-rich molecule that lacked aromatic and sulfur-containing amino acids. The overall amino acid composition is hydrophobic. A lipid constituent was also identified; it was made up of at least two lipid components, which were unique to the H.8 molecule. The chemical nature of the association of the protein and lipid is presently unknown, but it is clearly a tenacious one.

scholarly journals Structure, Application, and Biochemistry of Microbial Keratinases

2021 ◽  
Vol 12 ◽  
Author(s):  
Qingxin Li
Keyword(s):  
Amino Acids ◽  
Disulfide Bonds ◽  
Biochemical Characterization ◽  
Value Added ◽  
Structural Studies ◽  
Biotechnological Application ◽  
Hard Tissues ◽  
Made In ◽  
Value Added Products

Keratinases belong to a class of proteases that are able to degrade keratins into amino acids. Microbial keratinases play important roles in turning keratin-containing wastes into value-added products by participating in the degradation of keratin. Keratin is found in human and animal hard tissues, and its complicated structures make it resistant to degradation by common proteases. Although breaking disulfide bonds are involved in keratin degradation, keratinase is responsible for the cleavage of peptides, making it attractive in pharmaceutical and feather industries. Keratinase can serve as an important tool to convert keratin-rich wastes such as feathers from poultry industry into diverse products applicable to many fields. Despite of some progress made in isolating keratinase-producing microorganisms, structural studies of keratinases, and biochemical characterization of these enzymes, effort is still required to expand the biotechnological application of keratinase in diverse fields by identifying more keratinases, understanding the mechanism of action and constructing more active enzymes through molecular biology and protein engineering. Herein, this review covers structures, applications, biochemistry of microbial keratinases, and strategies to improve its efficiency in keratin degradation.

Discovery and Biocatalytic Application of a PLP-Dependent Amino Acid γ-Substitution Enzyme that Catalyzes C-C Bond Formation

2020 ◽  
Author(s):  
Mengbin Chen ◽  
Chun-Ting Liu ◽  
Yi Tang
Keyword(s):  
Amino Acids ◽  
Biosynthetic Pathway ◽  
Pyridoxal Phosphate ◽  
Biochemical Characterization ◽  
Indole Alkaloid ◽  
Building Blocks ◽  
Nucleophilic Attack ◽  
Keto Esters ◽  
Key Enzyme

Pyridoxal phosphate (PLP)-dependent enzymes can catalyze various transformations of amino acids at alpha, beta, and gamma positions. These versatile enzymes are prominently involved in the biosynthesis of nonproteinogenic amino acids as building blocks of natural products, and are attractive biocatalysts. Here, we report the discovery of a two-step enzymatic synthesis of (2<i>S, </i>6<i>S</i>)-6-methyl pipecolate <b>1</b>, from the biosynthetic pathway of indole alkaloid citrinadin. The key enzyme CndF is PLP-dependent and catalyzes synthesis of (<i>S</i>)-2-amino-6-oxoheptanoate <b>3</b> that is in equilibrium with the cyclic Schiff base. The second enzyme CndE is a stereoselective imine reductase that gives <b>1</b>. Biochemical characterization of CndF showed this enzyme performs gamma-elimination of <i>O</i>-acetyl L-homoserine to generate the vinylglycine ketimine, which is subjected to nucleophilic attack by acetoacetate to form the new C<sub>gamma</sub>-C<sub>delta</sub> bond in <b>3 </b>and complete the gamma-substitution reaction. CndF displays substrate promiscuity towards different beta-keto carboxylate and esters. Using a recombinant <i>Aspergillus </i>strain expressing CndF and CndE, feeding various alkyl-beta-keto esters led to the biosynthesis of 6-substituted L-pipecolates. The discovery of CndF expands the repertoire of reactions that can be catalyzed by PLP-dependent enzymes.

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