Asymmetric alkylation of chiral .beta.-lactam ester enolates. A new approach to the synthesis of .alpha.-alkylated .alpha.-amino acids

1987 ◽  
Vol 109 (21) ◽  
pp. 6537-6538 ◽  
Author(s):  
Iwao Ojima ◽  
Xiaogang Qiu
Keyword(s):  
Amino Acids ◽  
Beta Lactam ◽  
New Approach ◽  
Asymmetric Alkylation

scholarly journals Avoided motifs: short amino acid strings missing from protein datasets

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Pablo Mier ◽  
Miguel A. Andrade-Navarro
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Function ◽  
Large Protein ◽  
New Approach ◽  
Cellular Context ◽  
Human Proteins ◽  
Context Specific ◽  
Protein Datasets

Abstract According to the amino acid composition of natural proteins, it could be expected that all possible sequences of three or four amino acids will occur at least once in large protein datasets purely by chance. However, in some species or cellular context, specific short amino acid motifs are missing due to unknown reasons. We describe these as Avoided Motifs, short amino acid combinations missing from biological sequences. Here we identify 209 human and 154 bacterial Avoided Motifs of length four amino acids, and discuss their possible functionality according to their presence in other species. Furthermore, we determine two Avoided Motifs of length three amino acids in human proteins specifically located in the cytoplasm, and two more in secreted proteins. Our results support the hypothesis that the characterization of Avoided Motifs in particular contexts can provide us with information about functional motifs, pointing to a new approach in the use of molecular sequences for the discovery of protein function.

Coupling of Steroid O-(Carboxymethyl)oxime Derivatives with Amino Alcohols

1996 ◽  
Vol 61 (2) ◽  
pp. 288-297 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý
Keyword(s):  
Amino Acids ◽  
Hydroxy Group ◽  
Building Blocks ◽  
Amino Alcohols ◽  
New Approach ◽  
Alternative Synthesis ◽  
Oxime Derivatives ◽  
A Chain ◽  
Derivatives Of

New approach to the preparation of steroids with connecting bridge, based on an O-carboxymethyloxime (CMO) structure, and with terminal hydroxy group, is presented. 17-CMO derivatives of 3β-acetoxy- and 3β-methoxymethoxyandrost-5-en-17-one were condensed with α,ω-amino alcohols to give derivatives with a chain of seven to nine atoms. After THP-protection, these compounds were converted to 3-keto-4-ene derivatives. An alternative synthesis consisted in transformation of 17-CMO derivatives with bonded amino acids by reduction of the terminal carboxyl. The resulting compounds were designed as building blocks for the preparation of bis-haptens for sandwich immunoassays.

New approach to the synthesis of α-halogenomethyl-α-amino acids

1978 ◽  
Vol 19 (14) ◽  
pp. 1215-1218 ◽  
Author(s):  
P. Bey ◽  
J.P. Vevert
Keyword(s):  
Amino Acids ◽  
New Approach

Enzymatic Dynamic Kinetic Resolution of Oxazinones: A New Approach to Enantiopure β2-Amino Acids

ChemCatChem ◽  
2011 ◽  
Vol 3 (2) ◽  
pp. 319-330 ◽  
Author(s):  
Albrecht Berkessel ◽  
Ilona Jurkiewicz ◽  
Resmi Mohan
Keyword(s):  
Amino Acids ◽  
Kinetic Resolution ◽  
Dynamic Kinetic Resolution ◽  
New Approach

ChemInform Abstract: A NEW APPROACH FOR ESTERIFICATION OF AMINO ACIDS

1978 ◽  
Vol 9 (11) ◽  
Author(s):  
J. C. JAIN ◽  
I. K. SHARMA ◽  
M. K. SAHNI ◽  
K. C. GUPTA ◽  
N. K. MATHUR
Keyword(s):  
Amino Acids ◽  
New Approach

scholarly journals Amino Acid-Mediated Induction of the Basic Amino Acid-Specific Outer Membrane Porin OprD from Pseudomonas aeruginosa

1999 ◽  
Vol 181 (17) ◽  
pp. 5426-5432 ◽  
Author(s):  
Martina M. Ochs ◽  
Chung-Dar Lu ◽  
Robert E. W. Hancock ◽  
Ahmed T. Abdelal
Keyword(s):  
Amino Acids ◽  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Regulatory Protein ◽  
Basic Amino Acid ◽  
Sole Source ◽  
Activation Mechanism ◽  
Beta Lactam ◽  
Mobility Shift ◽  
Carbon And Nitrogen

ABSTRACT Pseudomonas aeruginosa can utilize arginine and other amino acids as both carbon and nitrogen sources. Earlier studies have shown that the specific porin OprD facilitates the diffusion of basic amino acids as well as the structurally analogous beta-lactam antibiotic imipenem. The studies reported here showed that the expression of OprD was strongly induced when arginine, histidine, glutamate, or alanine served as the sole source of carbon. The addition of succinate exerted a negative effect on induction ofoprD, likely due to catabolite repression. The arginine-mediated induction was dependent on the regulatory protein ArgR, and binding of purified ArgR to its operator upstream of theoprD gene was demonstrated by gel mobility shift and DNase assays. The expression of OprD induced by glutamate as the carbon source, however, was independent of ArgR, indicating the presence of more than a single activation mechanism. In addition, it was observed that the levels of OprD responded strongly to glutamate and alanine as the sole sources of nitrogen. Thus, that the expression ofoprD is linked to both carbon and nitrogen metabolism ofPseudomonas aeruginosa.

scholarly journals A Protein-Based Material from a New Approach Using Whole Defatted Larvae, and Its Interaction with Moisture

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 287 ◽  
Author(s):  
Nazanin Alipour ◽  
Björn Vinnerås ◽  
Fabrice Gouanvé ◽  
Eliane Espuche ◽  
Mikael S. Hedenqvist
Keyword(s):  
Amino Acids ◽  
Animal Feed ◽  
Saturated Fatty Acids ◽  
Moisture Sorption ◽  
Essential Amino Acids ◽  
Moisture Diffusivity ◽  
Size Analysis ◽  
Moisture Uptake ◽  
New Approach ◽  
Moisture Sorption Isotherm

A protein-based material created from a new approach using whole defatted larvae of the Black Soldier fly is presented. The larvae turn organic waste into their own biomass with high content of protein and lipids, which can be used as animal feed or for material production. After removing the larva lipid and adding a plasticizer, the ground material was compression molded into plates/films. The lipid, rich in saturated fatty acids, can be used in applications such as lubricants. The amino acids present in the greatest amounts were the essential amino acids aspartic acid/asparagine and glutamic acid/glutamine. Infrared spectroscopy revealed that the protein material had a high amount of strongly hydrogen-bonded β-sheets, indicative of a highly aggregated protein. To assess the moisture–protein material interactions, the moisture uptake was investigated. The moisture uptake followed a BET type III moisture sorption isotherm, which could be fitted to the Guggenheim, Anderson and de Boer (GAB) equation. GAB, in combination with cluster size analysis, revealed that the water clustered in the material already at a low moisture content and the cluster increased in size with increasing relative humidity. The clustering also led to a peak in moisture diffusivity at an intermediate moisture uptake.

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