scholarly journals Characterization of Amino Acid Substitutions in the Putative Binding Site of Bupropion in Glic

2020 ◽  
Vol 118 (3) ◽  
pp. 583a
Author(s):  
Dubem Onyejegbu ◽  
Jessica Shepherd ◽  
Elham Pirayesh ◽  
Akash Pandhare ◽  
Zackary R. Gallardo ◽  
...  
Keyword(s):  
Amino Acid ◽  
Binding Site ◽  
Amino Acid Substitutions ◽  
Putative Binding Site

scholarly journals Characterization of H9N2 influenza A viruses isolated from chicken products imported into Japan from China

2006 ◽  
Vol 135 (3) ◽  
pp. 386-391 ◽  
Author(s):  
M. MASE ◽  
M. ETO ◽  
K. IMAI ◽  
K. TSUKAMOTO ◽  
S. YAMAGUCHI
Keyword(s):  
Influenza Virus ◽  
Amino Acid ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Influenza A ◽  
H9n2 Virus ◽  
Amino Acid Substitutions ◽  
Influenza A Viruses ◽  
Potential Sources

We characterized eleven H9N2 influenza A viruses isolated from chicken products imported from China. Genetically they were classified into six distinct genotypes, including five already known genotypes and one novel genotype. This suggested that such multiple genotypes of the H9N2 virus have possibly already become widespread and endemic in China. Two isolates have amino-acid substitutions that confer resistance to amantadine in the M2 region, and this supported the evidence that this mutation might be a result of the wide application of amantadine for avian influenza treatment in China. These findings emphasize the importance of surveillance for avian influenza virus in this region, and of quarantining imported chicken products as potential sources for the introduction of influenza virus.

scholarly journals Amino acid substitutions in human growth hormone affect coiled-coil content and receptor binding

2021 ◽  
Author(s):  
Andrei Rajkovic ◽  
Sandesh Kanchugal ◽  
Eldar Abdurakhmanov ◽  
Rebecca Howard ◽  
Astrid Gräslund ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Binding Site ◽  
Human Growth Hormone ◽  
Receptor Binding ◽  
Coiled Coil ◽  
Human Growth ◽  
Zinc Binding ◽  
Amino Acid Substitutions ◽  
Great Relevance

The interaction between human Growth Hormone (hGH) and hGH Receptor (hGHR) has great relevance to human diseases such as acromegaly and cancer. HGH has been extensively engineered by other workers to improve binding and other properties. We used a computational screen to select substitutions at single hGH positions within the hGHR-binding site. We find that, while many successfully slow down dissociation of the hGH-hGHR complex once bound, they also slow down the association of hGH to hGHR. We are particularly interested in E174 which belongs to the hGH zinc-binding triad, and which spans coiled-coil helices and obeys the coiled-coil heptad pattern. Surprisingly, substituting E174 with A leads to substantial increase in an experimental measure of coiled-coil content. E174A is known to increase affinity of hGH against hGHR; here we show that this is simply because the off-rate is slowed down more than the on-rate, in line with what has been found for other affinity-improving mutations. For E174Y (and mutations at other sites) the slowdown in on-rate was greater, leading to decreased affinity. The results point to a link between coiled-coiling, zinc binding, and hGHR-binding affinity in hGH, and also suggest rules for choosing affinity-increasing substitutions.

scholarly journals Characterization of amino acid substitutions in feline coronavirus 3C-like protease from a cat with feline infectious peritonitis treated with a protease inhibitor

2019 ◽  
Vol 237 ◽  
pp. 108398 ◽  
Author(s):  
Krishani Dinali Perera ◽  
Athri D. Rathnayake ◽  
Hongwei Liu ◽  
Niels C. Pedersen ◽  
William C. Groutas ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protease Inhibitor ◽  
Amino Acid Substitutions ◽  
Feline Infectious Peritonitis ◽  
Feline Coronavirus

scholarly journals Diversity of TEM Mutants in Proteus mirabilis

1999 ◽  
Vol 43 (11) ◽  
pp. 2671-2677 ◽  
Author(s):  
R. Bonnet ◽  
C. De Champs ◽  
D. Sirot ◽  
C. Chanal ◽  
R. Labia ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitution ◽  
Proteus Mirabilis ◽  
Clinical Isolates ◽  
Amino Acid Substitutions ◽  
First Report ◽  
Conjugative Plasmids ◽  
Extended Spectrum ◽  
Nucleotide Mutation

ABSTRACT In a survey of resistance to amoxicillin among clinical isolates ofProteus mirabilis, 10 TEM-type β-lactamases were characterized: (i) the well-known penicillinases TEM-1 and TEM-2, the extended-spectrum β-lactamases (ESBLs) TEM-3 and TEM-24, and the inhibitor-resistant TEM (IRT) TEM-44 and (ii) five novel enzymes, a penicillinase TEM-57 similar to TEM-1, an ESBL TEM-66 similar to TEM-3, and three IRTs, TEM-65, TEM-73, and TEM-74. The penicillinase TEM-57 and the ESBL TEM-66 differed from TEM-1 and TEM-3, respectively, by the amino acid substitution Gly-92→Asp (nucleotide mutation G-477→A). This substitution could have accounted for the decrease in pIs (5.2 for TEM-57 and 6.0 for TEM-66) but did not necessarily affect the intrinsic activities of these enzymes. The IRT TEM-65 was an IRT-1-like IRT (Cys-244) related to TEM-2 (Lys-39). The two other IRTs, TEM-73 and TEM-74, were related to IRT-1 (Cys-244) and IRT-2 (Ser-244), respectively, and harbored the amino acid substitutions Leu-21→Phe and Thr-265→Met. In this study, the ESBLs TEM-66, TEM-24, and TEM-3 were encoded by large (170- to 180-kb) conjugative plasmids that exhibited similar patterns after digestion and hybridization with the TEM and AAC(6′)I probes. The three IRTs TEM-65, TEM-73, and TEM-74 were encoded by plasmids that ranged in size from 42 to 70 kb but for which no transfer was obtained. The characterization of five new plasmid-mediated TEM-type β-lactamases and the first report of TEM-24 in P. mirabilis are evidence of the wide diversity of β-lactamases produced in this species and of its possible role as a β-lactamase-encoding plasmid reservoir.

Characterization of Six Mutations in Five Spanish Patients with Mitochondrial Acetoacetyl-CoA Thiolase Deficiency: Effects of Amino Acid Substitutions on Tertiary Structure

2002 ◽  
Vol 75 (3) ◽  
pp. 235-243 ◽  
Author(s):  
Toshiyuki Fukao ◽  
Haruki Nakamura ◽  
Kozue Nakamura ◽  
Celia Perez-Cerda ◽  
Antonio Baldellou ◽  
...  
Keyword(s):  
Amino Acid ◽  
Tertiary Structure ◽  
Amino Acid Substitutions

Development and Characterization of Peptidic Fusion Inhibitors Derived from HIV-1 gp41 with Partial D-Amino Acid Substitutions

ChemMedChem ◽  
2009 ◽  
Vol 4 (4) ◽  
pp. 570-581 ◽  
Author(s):  
Fabrice Gaston ◽  
Giovana C. Granados ◽  
Sergio Madurga ◽  
Francesc Rabanal ◽  
Faouzi Lakhdar-Ghazal ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitutions ◽  
Fusion Inhibitors ◽  
Hiv 1

scholarly journals Biochemical characterization of polypeptides encoded by mutated human Ha-ras1 genes.

1986 ◽  
Vol 6 (2) ◽  
pp. 730-734 ◽  
Author(s):  
W W Colby ◽  
J S Hayflick ◽  
S G Clark ◽  
A D Levinson
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Kinase Activity ◽  
Biochemical Characterization ◽  
Strong Support ◽  
Guanine Nucleotides ◽  
Amino Acid Substitutions ◽  
Gtpase Activity ◽  
P21 Ras

We expressed six forms of p21-ras polypeptides in Escherichia coli with differing transformation potentials resulting from amino acid substitutions at position 12. The ability of the encoded p21's to autophosphorylate, bind guanine nucleotides, and hydrolyze GTP was assessed. All versions of p21 bound GTP equivalently; the kinase activity, while dependent upon residue 12, did not correlate with the transforming potential of the polypeptide. All transforming versions exhibited an impaired GTPase activity, while a novel nontransforming derivative [p21(pro-12)] possessed an enhanced GTPase activity. These results provide strong support for the proposal that an impairment of the cellular p21 GTPase activity can unmask its transforming potential.

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