scholarly journals Front Cover: Single Amino Acid Replacement in G‐7039 Leads to a 70‐fold Increase in Binding toward GHS‐R1a (ChemMedChem 20/2019)

ChemMedChem ◽  
2019 ◽  
Vol 14 (20) ◽  
pp. 1743-1743
Author(s):  
Tyler Lalonde ◽  
Milan M. Fowkes ◽  
Jinqiang Hou ◽  
Pierre E. Thibeault ◽  
Mark Milne ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fold Increase ◽  
Amino Acid Replacement ◽  
Single Amino Acid ◽  
Front Cover

Single Amino Acid Replacement in G‐7039 Leads to a 70‐fold Increase in Binding toward GHS‐R1a

ChemMedChem ◽  
2019 ◽  
Vol 14 (20) ◽  
pp. 1762-1766
Author(s):  
Tyler Lalonde ◽  
Milan M. Fowkes ◽  
Jinqiang Hou ◽  
Pierre E. Thibeault ◽  
Mark Milne ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fold Increase ◽  
Amino Acid Replacement ◽  
Single Amino Acid

A Single Amino Acid Replacement Results in the Ca2+-Induced Self-Assembly of a Helical Conantokin-Based Peptide†

Biochemistry ◽  
2004 ◽  
Vol 43 (41) ◽  
pp. 13225-13232 ◽  
Author(s):  
Qiuyun Dai ◽  
Francis J. Castellino ◽  
Mary Prorok
Keyword(s):  
Amino Acid ◽  
Self Assembly ◽  
Amino Acid Replacement ◽  
Single Amino Acid

Calcium binding to abnormal fibrinogens with a single amino acid replacement in the NH2-terminal region of fibrin α - or β-chain

1992 ◽  
Vol 67 (5) ◽  
pp. 613-618 ◽  
Author(s):  
Nobuhiko Yoshida ◽  
Hajime Hirata ◽  
Shinji Asakura ◽  
Kensuke Yamazumi ◽  
Michio Matsuda ◽  
...  
Keyword(s):  
Amino Acid ◽  
Calcium Binding ◽  
Amino Acid Replacement ◽  
Terminal Region ◽  
Single Amino Acid ◽  
Β Chain

scholarly journals Alterations in Penicillin-Binding Protein 1A Confer Resistance to β-Lactam Antibiotics in Helicobacter pylori

2002 ◽  
Vol 46 (7) ◽  
pp. 2229-2233 ◽  
Author(s):  
M. M. Gerrits ◽  
D. Schuijffel ◽  
A. A. van Zwet ◽  
E. J. Kuipers ◽  
C. M. J. E. Vandenbroucke-Grauls ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Amino Acid ◽  
Amino Acid Substitution ◽  
Binding Protein ◽  
Resistance Mechanism ◽  
Fold Increase ◽  
Single Amino Acid ◽  
Penicillin Binding Protein ◽  
H Pylori ◽  
High Level

ABSTRACT Most Helicobacter pylori strains are susceptible to amoxicillin, an important component of combination therapies for H. pylori eradication. The isolation and initial characterization of the first reported stable amoxicillin-resistant clinical H. pylori isolate (the Hardenberg strain) have been published previously, but the underlying resistance mechanism was not described. Here we present evidence that the β-lactam resistance of the Hardenberg strain results from a single amino acid substitution in HP0597, a penicillin-binding protein 1A (PBP1A) homolog of Escherichia coli. Replacement of the wild-type HP0597 (pbp1A) gene of the amoxicillin-sensitive (Amxs) H. pylori strain 1061 by the Hardenberg pbp1A gene resulted in a 100-fold increase in the MIC of amoxicillin. Sequence analysis of pbp1A of the Hardenberg strain, the Amxs H. pylori strain 1061, and four amoxicillin-resistant (Amxr) 1061 transformants revealed a few amino acid substitutions, of which only a single Ser414→Arg substitution was involved in amoxicillin resistance. Although we cannot exclude that mutations in other genes are required for high-level amoxicillin resistance of the Hardenberg strain, this amino acid substitution in PBP1A resulted in an increased MIC of amoxicillin that was almost identical to that for the original Hardenberg strain.

scholarly journals Cloning of rat asparagine synthetase and specificity of the amino acid-dependent control of its mRNA content

1994 ◽  
Vol 304 (3) ◽  
pp. 745-750 ◽  
Author(s):  
R G Hutson ◽  
M S Kilberg
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Culture Medium ◽  
Fold Increase ◽  
Trna Synthetase ◽  
Asparagine Synthetase ◽  
Single Amino Acid ◽  
General Control ◽  
Nutrient Regulation ◽  
Mrna Content

A full-length cDNA clone for rat asparagine synthetase (AS) was isolated from a cDNA library enriched for amino acid-regulated sequences. The AS cDNA was used to investigate the amino acid-dependent repression of AS mRNA content in rat Fao hepatoma cells. In response to complete amino acid starvation, there was an approximately 10-fold increase in the level of AS mRNA. Three species of mRNA, of approx. sizes 2.0, 2.5 and 4.0 kb, were detected and each was simultaneously regulated to the same degree. The expression of AS mRNA increased by 6 h after removal of amino acids, reached a plateau after 9 h, and was blocked by either actinomycin D or cycloheximide. Partial repression of the AS mRNA content was maintained by the presence of a single amino acid in the culture medium, but the degree of effectiveness for each one varied widely. Glutamine showed the greatest ability to repress the AS mRNA content, even at an extracellular concentration 10 times below its plasma level. Other effective repressors included the amino acids asparagine, histidine and leucine, as well as ammonia. Depletion of selected single amino acids from an otherwise complete culture medium also caused up-regulation. In particular, removal of histidine, threonine or tryptophan from the medium, or the addition of histidinol to inhibit histidinyl-tRNA synthetase, resulted in a significant increase in AS mRNA content. The data indicate that nutrient regulation of AS mRNA occurs by a general control mechanism that is responsive to a spectrum of amino acids.

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