A New Variant with Two Amino Acid Substitutions: Hb S‐Cameroon [β6(A3)Glu→Val;β90(F6)Glu→Lys]

Hemoglobin ◽  
2004 ◽  
Vol 28 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Jens R. Bundgaard ◽  
Ole W. Bjerrum ◽  
Anne Tybjærg‐Hansen
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitutions ◽  
New Variant ◽  
Hb S

Hb S-San Martin: A New Sickling Hemoglobin With Two Amino Acid Substitutions [β6(A3)Glu→Val;β105(G7)Leu→Pro] In An Argentinean Family

Hemoglobin ◽  
2010 ◽  
Vol 34 (5) ◽  
pp. 500-504 ◽  
Author(s):  
Aurora Feliu-Torres ◽  
Silvia Eandi Eberle ◽  
Irma M. Bragós ◽  
Gabriela Sciuccati ◽  
Mara J. Ojeda ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Substitutions ◽  
Hb S ◽  
San Martín

scholarly journals Characterization of Chromosome-Mediated BlaOXA-894 in Shewanella xiamenensis Isolated from Pig Wastewater

2019 ◽  
Vol 16 (19) ◽  
pp. 3768
Author(s):  
Huiyun Zou ◽  
Ziyu Zhou ◽  
Huiyu Xia ◽  
Qian Zhao ◽  
Xuewen Li
Keyword(s):  
Amino Acid ◽  
Rural China ◽  
Water Environment ◽  
Amino Acid Substitutions ◽  
Gene Encoding ◽  
Potential Health ◽  
Carbapenem Resistant ◽  
Gene Environment ◽  
New Variant ◽  
Its Gene

A new variant of the blaOXA-546 gene, namely blaOXA-894, was identified on the chromosome of Shewanella xiamenensis isolated from pig wastewater in rural China. OXA-894 differs from OXA-546 (A46V, I219del) and OXA-48 (T167I, I219del) with two amino acid substitutions, respectively. The isolate was resistant to ampicillin, aztreonam, imipenem, meropenem and fosfomycin. Carba NP test confirmed S. xiamenensis strain sx20 as a carbapenemase-producer. The blaOXA-894 gene was located between the gene encoding a LysR family transcriptional regulator and the C15 gene. Its gene environment was similar to other S. xiamenensis with chromosome-located blaOXA-48-like genes. The T24H and T94V amino acid substitutions of LuxS protein were predicted to be deleterious, which may affect the virulence phenotype. The occurrence and potential health risk of carbapenem-resistant S. xiamenensis in a water environment is of concern.

scholarly journals A New Evolutionary Variant of the Streptogramin A Resistance Protein, Vga(A)LC, from Staphylococcus haemolyticus with Shifted Substrate Specificity towards Lincosamides

2006 ◽  
Vol 50 (12) ◽  
pp. 4070-4076 ◽  
Author(s):  
G. Novotna ◽  
J. Janata
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Resistance Gene ◽  
Atp Binding ◽  
Amino Acid Substitutions ◽  
Abc Proteins ◽  
Susceptible Host ◽  
Staphylococcus Haemolyticus ◽  
New Variant ◽  
Transport Experiment

ABSTRACT We found a new variant of the streptogramin A resistance gene, vga(A)LC, in clinical isolates of Staphylococcus haemolyticus resistant to lincomycin and clindamycin but susceptible to erythromycin and in which no relevant lincosamide resistance gene was detected. The gene vga(A)LC, differing from the gene vga(A) at the protein level by seven amino acid substitutions, was present exclusively in S. haemolyticus strains resistant to both lincosamides and streptogramin A (LSA phenotype). Antibiotic resistance profiles of the ATP-binding cassette (ABC) proteins Vga(A)LC and Vga(A) in the antibiotic-susceptible host S. aureus RN4220 were compared. It was shown that Vga(A)LC conferred resistance to both lincosamides and streptogramin A, while Vga(A) conferred significant resistance to streptogramin A only. Detailed analysis of the seven amino acid substitutions, distinguishing the two related ABC proteins with different substrate specificities, identified the substrate-recognizing site: four clustered substitutions (L212S, G219V, A220T, and G226S) in the spacer between the two ATP-binding cassettes altered the substrate specificity and constituted the lincosamide-streptogramin A resistance phenotype. A transport experiment with radiolabeled lincomycin demonstrated that the mechanism of lincosamide resistance in S. haemolyticus was identical to that of the reported macrolide-streptogramin B resistance conferred by Msr(A).

scholarly journals Emergence in Southern France of a new SARS-CoV-2 variant of probably Cameroonian origin harbouring both substitutions N501Y and E484K in the spike protein

2021 ◽  
Author(s):  
Philippe Colson ◽  
Jeremy Delerce ◽  
Emilie Burel ◽  
Jordan Dahan ◽  
Agnes Jouffret ◽  
...  
Keyword(s):  
Amino Acid ◽  
Geographical Area ◽  
Sister Group ◽  
Spike Protein ◽  
Phylogenetic Position ◽  
Amino Acid Substitutions ◽  
Nucleotide Substitutions ◽  
Oxford Nanopore ◽  
New Variant ◽  
Previous Definition

SARS-CoV-2 variants have become a major virological, epidemiological and clinical concern, particularly with regard to the risk of escape from vaccine-induced immunity. Here we describe the emergence of a new variant. For twelve SARS-CoV-positive patients living in the same geographical area of southeastern France, qPCR testing that screen for variant-associated mutations showed an atypical combination. The index case returned from a travel in Cameroon. The genomes were obtained by next-generation sequencing with Oxford Nanopore Technologies on GridION instruments within approximately 8 h. Their analysis revealed 46 mutations and 37 deletions resulting in 30 amino acid substitutions and 12 deletions. Fourteen amino acid substitutions, including N501Y and E484K, and 9 deletions are located in the spike protein. This genotype pattern led to create a new Pangolin lineage named B.1.640.2, which is a phylogenetic sister group to the old B.1.640 lineage renamed B.1.640.1. Both lineages differ by 25 nucleotide substitutions and 33 deletions. The mutation set and phylogenetic position of the genomes obtained here indicate based on our previous definition a new variant we named 'IHU'. These data are another example of the unpredictability of the emergence of SARS-CoV-2 variants, and of their introduction in a given geographical area from abroad.

Recombinant Variants of Tissue-Type Plasminogen Activator Containing Amino Acid Substitutions in the Finger Domain

1992 ◽  
Vol 68 (06) ◽  
pp. 672-677 ◽  
Author(s):  
Hitoshi Yahara ◽  
Keiji Matsumoto ◽  
Hiroyuki Maruyama ◽  
Tetsuya Nagaoka ◽  
Yasuhiro Ikenaka ◽  
...  
Keyword(s):  
Amino Acid ◽  
Plasminogen Activator ◽  
Half Life ◽  
Tissue Type ◽  
Clot Lysis ◽  
Amino Acid Substitutions ◽  
Wild Type ◽  
Plasma Clot ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator

SummaryTissue-type plasminogen activator (t-PA) is a fibrin-specific agent which has been used to treat acute myocardial infarction. In an attempt to clarify the determinants for its rapid clearance in vivo and high affinity for fibrin clots, we produced five variants containing amino acid substitutions in the finger domain, at amino acid residues 7–9, 10–14, 15–19, 28–33, and 37–42. All the variants had a prolonged half-life and a decreased affinity for fibrin of various degrees. The 37–42 variant demonstrated about a 6-fold longer half-life with a lower affinity for fibrin. Human plasma clot lysis assay estimated the fibrinolytic activity of the 37–42 variant to be 1.4-fold less effective than that of the wild-type rt-PA. In a rabbit jugular vein clot lysis model, doses of 1.0 and 0.15 mg/kg were required for about 70% lysis in the wild-type and 37–42 variant, respectively. Fibrinogen was degraded only when the wild-type rt-PA was administered at a dose of 1.0 mg/kg. These findings suggest that the 37–42 variant can be employed at a lower dosage and that it is a more fibrin-specific thrombolytic agent than the wild-type rt-PA.

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