A Single Amino-Acid in the TM1 Domain Is an Important Determinant of the Desensitization Kinetics of Recombinant Human and Guinea Pig α-Homomeric 5-Hydroxytryptamine Type 3 Receptors

2001 ◽  
Vol 59 (4) ◽  
pp. 844-851 ◽  
Author(s):  
Nicole Lobitz ◽  
Günter Gisselmann ◽  
Hanns Hatt ◽  
Christian H. Wetzel
Keyword(s):  
Amino Acid ◽  
Guinea Pig ◽  
Important Determinant ◽  
Single Amino Acid ◽  
Type 3 ◽  
Kinetics Of

scholarly journals Single nucleotide polypmorphisms of fimH associated with adherence and biofilm formation by serovars of Salmonella enterica

Microbiology ◽  
2011 ◽  
Vol 157 (11) ◽  
pp. 3162-3171 ◽  
Author(s):  
Brett E. Dwyer ◽  
Karly L. Newton ◽  
Dagmara Kisiela ◽  
Evgeni V. Sokurenko ◽  
Steven Clegg
Keyword(s):  
Amino Acid ◽  
Guinea Pig ◽  
Biofilm Formation ◽  
Allelic Variation ◽  
Single Amino Acid ◽  
Predicted Amino Acid Sequence ◽  
Nucleotide Polymorphisms ◽  
Cell Type ◽  
Single Nucleotide

Type 1 fimbriae produced by serovars of Salmonella are characterized by their ability to agglutinate guinea pig erythrocytes in the absence of d-mannose but not in its presence. The FimH protein is the adhesin that mediates this reaction; it is distinct from the major fimbrial protei.n (FimA) that composes the fimbrial shaft. Avian-adapted serovars of Salmonella produce non-haemagglutinating fimbriae that have been reported to mediate adherence to avian cells. A single amino acid substitution is present in the FimH adhesin of these strains compared to that of a Typhimurium isolate. Also, previous studies have shown that single nucleotide polymorphisms in two strains of the Typhimurium fimH alter the binding specificity. We therefore investigated the allelic variation of fimH from a range of serotypes (both host-adapted and non-host-adapted) and isolates of Salmonella. Most FimH adhesins mediated the mannose-sensitive haemagglutination of guinea pig erythrocytes, but many did not facilitate adherence to HEp-2 cells. A small number of isolates also produced fimbriae but did not mediate adherence to either cell type. Transformants possessing cloned fimH genes exhibited a number of different substitutions within the predicted amino acid sequence of the FimH polypeptide. No identical FimH amino sequence was found between strains that adhere to erythrocytes and/or HEp-2 cells and those produced by non-adherent strains. FimH-mediated adherence to HEp-2 cells was invariably associated with the ability to form biofilms on mannosylated bovine serum albumin.

scholarly journals A Single Amino Acid Alteration in the Human Parainfluenza Virus Type 3 Hemagglutinin-Neuraminidase Glycoprotein Confers Resistance to the Inhibitory Effects of Zanamivir on Receptor Binding and Neuraminidase Activity

2001 ◽  
Vol 75 (14) ◽  
pp. 6310-6320 ◽  
Author(s):  
Matthew T. Murrell ◽  
Matteo Porotto ◽  
Olga Greengard ◽  
Natalia Poltoratskaia ◽  
Anne Moscona
Keyword(s):  
Sialic Acid ◽  
Amino Acid ◽  
Virus Type ◽  
Parainfluenza Virus ◽  
Single Amino Acid ◽  
Plaque Morphology ◽  
Human Parainfluenza Virus ◽  
Type 3 ◽  
Acid Alteration ◽  
Amino Acid Alteration

ABSTRACT Entry and fusion of human parainfluenza virus type 3 (HPF3) requires interaction of the viral hemagglutinin-neuraminidase (HN) glycoprotein with its sialic acid receptor. 4-Guanidino-2,4-dideoxy-2,3-dehydro-N-acetylneuraminic acid (4-GU-DANA; zanamivir), a sialic acid transition-state analog designed to fit the influenza virus neuraminidase catalytic site, possesses antiviral activity at nanomolar concentrations in vitro. We have shown previously that 4-GU-DANA also inhibits both HN-mediated binding of HPF3 to host cell receptors and HN's neuraminidase activity. In the present study, a 4-GU-DANA-resistant HPF3 virus variant (ZM1) was generated by serial passage in the presence of 4-GU-DANA. ZM1 exhibited a markedly fusogenic plaque morphology and harbored two HN gene mutations resulting in two amino acid alterations, T193I and I567V. Another HPF3 variant studied in parallel, C-0, shared an alteration at T193 and exhibited similar plaque morphology but was not resistant to 4-GU-DANA. Neuraminidase assays revealed a 15-fold reduction in 4-GU-DANA sensitivity for ZM1 relative to the wild type (WT) and C-0. The ability of ZM1 to bind sialic acid receptors was inhibited 10-fold less than for both WT and C-0 in the presence of 1 mM 4-GU-DANA. ZM1 also retained infectivity at 15-fold-higher concentrations of 4-GU-DANA than WT and C-0. A single amino acid alteration at HN residue 567 confers these 4-GU-DANA-resistant properties. An understanding of ZM1 and other escape variants provides insight into the effects of this small molecule on HN function as well as the role of the HN glycoprotein in HPF3 pathogenesis.

scholarly journals Immune response of Lewis rats to peptide C1 (residues 68-88) of guinea pig and rat myelin basic proteins.

1977 ◽  
Vol 146 (5) ◽  
pp. 1323-1331 ◽  
Author(s):  
R F Kibler ◽  
R B Fritz ◽  
F Chou ◽  
Jen Chou C-H ◽  
N Y Peacocke ◽  
...  
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Amino Acid ◽  
Guinea Pig ◽  
Proliferative Response ◽  
Single Amino Acid ◽  
Helper Function ◽  
Circulating Antibodies ◽  
Stimulation Of

Peptide C1 (residues 68-88) from GP and rat BP differ by a single amino acid interchange at residue 79. This residue is serine in GP C1 and threonine in rat C1. GP C1 was encephalitogenic in Le rats at doses as low as 15 ng. Rat C1 was encephalitogenic at doses of 1,500 ng or greater. LNC from rats challenged with 25 X 10(-4) micronmol of GP C1 and 250 X 10(-4) micronmol of rat C1 showed a proliferative response in vitro to both peptides, but in each instance the magnitude of the response was greater to the GP peptide. GP C1 also induced higher levels of circulating antibodies at 25 X 10(-4) micronmol, but the specificity of antibodies produced by the two peptides was the same. These results have been interpreted as indicating that the presence of serine at position 79 in GP C1 results in the stimulation of greater numbers of T cells involved in (a) the induction of EAE, (b) the in vitro proliferative response and (c) helper function in antibody production.

Single Amino Acid Based Self-Assemblies of Cysteine and Methionine

2018 ◽  
Author(s):  
Nidhi Gour ◽  
Bharti Koshti ◽  
Chandra Kanth P. ◽  
Dhruvi Shah ◽  
Vivek Shinh Kshatriya ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Self Assembly ◽  
Aromatic Amino Acids ◽  
Neutral Condition ◽  
Single Amino Acid ◽  
Binding Assays ◽  
Human Neuroblastoma ◽  
Cytotoxicity Assays ◽  
First Time

We report for the very first time self-assembly of Cysteine and Methionine to discrenible strucutres under neutral condition. To get insights into the structure formation, thioflavin T and Congo red binding assays were done which revealed that aggregates may not have amyloid like characteristics. The nature of interactions which lead to such self-assemblies was purported by coincubating assemblies in urea and mercaptoethanol. Further interaction of aggregates with short amyloidogenic dipeptide diphenylalanine (FF) was assessed. While cysteine aggregates completely disrupted FF fibres, methionine albeit triggered fibrillation. The cytotoxicity assays of cysteine and methionine structures were performed on Human Neuroblastoma IMR-32 cells which suggested that aggregates are not cytotoxic in nature and thus, may not have amyloid like etiology. The results presented in the manuscript are striking, since to the best of our knowledge,this is the first report which demonstrates that even non-aromatic amino acids (cysteine and methionine) can undergo spontaneous self-assembly to form ordered aggregates.

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