scholarly journals One-step Metabolomics: Carbohydrates, Organic and Amino Acids Quantified in a Single Procedure

10.3791/2014 ◽  
2010 ◽  
Author(s):  
James D. Shoemaker
Keyword(s):  
Amino Acids ◽  
Single Procedure ◽  
One Step

scholarly journals In Vivo Identification of Intermediate Stages of the DNA Inversion Reaction Catalyzed by the Salmonella Hin Recombinase

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1649-1663
Author(s):  
Oliver Z Nanassy ◽  
Kelly T Hughes
Keyword(s):  
Amino Acids ◽  
Biochemical Analysis ◽  
Mutational Analysis ◽  
Recombination Reaction ◽  
Recombination Site ◽  
Dna Inversion ◽  
Hin Recombinase ◽  
One Step ◽  
A Site

Abstract The Hin recombinase catalyzes a site-specific recombination reaction that results in the reversible inversion of a 1-kbp segment of the Salmonella chromosome. The DNA inversion reaction catalyzed by the Salmonella Hin recombinase is a dynamic process proceeding through many intermediate stages, requiring multiple DNA sites and the Fis accessory protein. Biochemical analysis of this reaction has identified intermediate steps in the inversion reaction but has not yet revealed the process by which transition from one step to another occurs. Because transition from one reaction step to another proceeds through interactions between specific amino acids, and between amino acids and DNA bases, it is possible to study these transitions through mutational analysis of the proteins involved. We isolated a large number of mutants in the Hin recombinase that failed to carry out the DNA exchange reaction. We generated genetic tools that allowed the assignment of these mutants to specific transition steps in the recombination reaction. This genetic analysis, combined with further biochemical analysis, allowed us to define contributions by specific amino acids to individual steps in the DNA inversion reaction. Evidence is also presented in support of a model that Fis protein enhances the binding of Hin to the hixR recombination site. These studies identified regions within the Hin recombinase involved in specific transition steps of the reaction and provided new insights into the molecular details of the reaction mechanism.

scholarly journals Peculiarities of promiscuous l-threonine transaldolases for enantioselective synthesis of β-hydroxy-α-amino acids

2021 ◽  
Author(s):  
Shan Wang ◽  
Hai Deng
Keyword(s):  
Amino Acids ◽  
Organic Molecules ◽  
Stereoselective Synthesis ◽  
Enantioselective Synthesis ◽  
General Mechanism ◽  
Future Developments ◽  
Key Points ◽  
Biomaterial Science ◽  
One Step ◽  
Harsh Conditions

Abstract The introduction of β-hydroxy-α-amino acids (βHAAs) into organic molecules has received considerable attention as these molecules have often found widespread applications in bioorganic chemistry, medicinal chemistry and biomaterial science. Despite innovation of asymmetric synthesis of βHAAs, stereoselective synthesis to control the two chiral centres at Cα and Cβ positions is still challenging, with poor atomic economy and multi protection and deprotection steps. These syntheses are often operated under harsh conditions. Therefore, a biotransformation approach using biocatalysts is needed to selectively introduce these two chiral centres into structurally diverse molecules. Yet, there are few ways that enable one-step synthesis of βHAAs. One is to extend the substrate scope of the existing enzyme inventory. Threonine aldolases have been explored to produce βHAAs. However, the enzymes have poor controlled installation at Cβ position, often resulting in a mixture of diastereoisomers which are difficult to be separated. In this respect, l-threonine transaldolases (LTTAs) offer an excellent potential as the enzymes often provide controlled stereochemistry at Cα and Cβ positions. Another is to mine LTTA homologues and engineer the enzymes using directed evolution with the aim of finding engineered biocatalysts to accept broad substrates with enhanced conversion and stereoselectivity. Here, we review the development of LTTAs that incorporate various aldehyde acceptors to generate structurally diverse βHAAs and highlight areas for future developments. Key points • The general mechanism of the transaldolation reaction catalysed by LTTAs • Recent advances in LTTAs from different biosynthetic pathways • Applications of LTTAs as biocatalysts for production of βHAAs

ChemInform Abstract: AN EFFICIENT ONE-STEP REDUCTIVE N-MONOALKYLATION OF α-AMINO ACIDS

1984 ◽  
Vol 15 (36) ◽  
Author(s):  
Y. OHFUNE ◽  
N. KUROKAWA ◽  
N. HIGUCHI ◽  
M. SAITO ◽  
M. HASHIMOTO ◽  
...  
Keyword(s):  
Amino Acids ◽  
One Step

scholarly journals Random Transposon-Mediated Mutagenesis of the Essential Large Tegument Protein pUL36 of Pseudorabies Virus

2010 ◽  
Vol 84 (16) ◽  
pp. 8153-8162 ◽  
Author(s):  
Britta S. Möhl ◽  
Sindy Böttcher ◽  
Harald Granzow ◽  
Walter Fuchs ◽  
Barbara G. Klupp ◽  
...  
Keyword(s):  
Amino Acids ◽  
Pseudorabies Virus ◽  
Plaque Assay ◽  
Tegument Protein ◽  
Nuclear Pore ◽  
Viral Spread ◽  
One Step ◽  
Step Growth ◽  
Insertion Mutants

ABSTRACT Homologs of the pseudorabies virus (PrV) essential large tegument protein pUL36 are conserved throughout the Herpesviridae. pUL36 functions during transport of the nucleocapsid to and docking at the nuclear pore as well as during virion formation after nuclear egress in the cytoplasm. Deletion analyses revealed several nonessential regions within the 3,084-amino-acid PrV pUL36 (S. Böttcher, B. G. Klupp, H. Granzow, W. Fuchs, K. Michael, and T. C. Mettenleiter, J. Virol. 80:9910-9915, 2006; S. Böttcher, H. Granzow, C. Maresch, B. Möhl, B. G. Klupp, and T. C. Mettenleiter, J. Virol. 81:13403-13411, 2007), while the C-terminal 62 amino acids are essential for virus replication (K. Coller, J. Lee, A. Ueda, and G. Smith, J. Virol. 81:11790-11797, 2007). To identify additional functional domains, we performed random mutagenesis of PrV pUL36 by transposon-mediated insertion of a 15-bp linker. By this approach, 26 pUL36 insertion mutants were selected and tested in transient transfection assays for their ability to complement one-step growth and/or viral spread of a PrV UL36 null mutant. Ten insertion mutants in the N-terminal half and 10 in the C terminus complemented both, whereas six insertion mutants clustering in the center of the protein did not complement in either assay. Interestingly, several insertions within conserved parts yielded positive complementation, including those located within the essential C-terminal 62 amino acids. For 15 mutants that mediated productive replication, stable virus recombinants were isolated and further characterized by plaque assay, in vitro growth analysis, and electron microscopy. Except for three mutant viruses, most insertion mutants replicated like wild-type PrV. Two insertion mutants, at amino acids (aa) 597 and 689, were impaired in one-step growth and viral spread and exhibited a defect in virion maturation in the cytoplasm. In contrast, one functional insertion (aa 1800) in a region which otherwise yielded only nonfunctional insertion mutants was impaired in viral spread but not in one-step growth without a distinctive ultrastructural phenotype. In summary, these studies extend and refine previous analyses of PrV pUL36 and demonstrate the different sensitivities of different regions of the protein to functional loss by insertion.

scholarly journals Creation of a Broad-Range and Highly Stereoselectived-Amino Acid Dehydrogenase for the One-Step Synthesis ofd-Amino Acids

2006 ◽  
Vol 128 (33) ◽  
pp. 10923-10929 ◽  
Author(s):  
Kavitha Vedha-Peters ◽  
Manjula Gunawardana ◽  
J. David Rozzell ◽  
Scott J. Novick
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Dehydrogenase ◽  
Amino Acid Dehydrogenase ◽  
One Step ◽  
The One

scholarly journals Rational Enzyme Design Without Structural Knowledge: A Sequence-Based Approach for Efficient Generation of Glycosylation Catalysts

2020 ◽  
Author(s):  
David Teze ◽  
Zhao, Jiao ◽  
Mathias Wiemann ◽  
Zubaida Gulshan Kazi ◽  
Rossana Lupo ◽  
...  
Keyword(s):  
Amino Acids ◽  
Glycoside Hydrolase ◽  
Enzyme Engineering ◽  
Glycoside Hydrolases ◽  
Structural Knowledge ◽  
Enzyme Design ◽  
Engineering Approach ◽  
Efficient Generation ◽  
One Step ◽  
High Yields

<p>We present an enzyme engineering approach based solely on amino-acids sequence to convert glycoside hydrolases into transglycosylases. We demonstrate its effectiveness on enzymes form five different glycoside hydrolase families, synthesizing various oligosaccharides containing different α-/β-pyranosides or furanosides in one-step with high yields.</p>

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