scholarly journals Biophysical insights into a highly selective L-arginine-binding lipoprotein of a pathogenic treponeme

2018 ◽  
Author(s):  
Ranjit K. Deka ◽  
Wei Z. Liu ◽  
Shih-Chia Tso ◽  
Michael V. Norgard ◽  
Chad A. Brautigam
Keyword(s):  
Amino Acid ◽  
Single Molecule ◽  
Binding Protein ◽  
Treponema Pallidum ◽  
Titration Calorimetry ◽  
Biophysical Studies ◽  
Differential Scanning Fluorimetry ◽  
Periplasmic Proteins ◽  
Amino Acid Binding

ABSTRACTBiophysical and biochemical studies on the lipoproteins and other periplasmic proteins from the spirochetal speciesTreponema pallidumhave yielded numerous insights into the functioning of the organism’s peculiar membrane organization, its nutritional requirements, and intermediary metabolism. However, not allT. pallidumproteins have proven to be amenable to biophysical studies. One such recalcitrant protein is Tp0309, a putative polar-amino-acid-binding protein of an ABC transporter system. To gain further information on its possible function, a homolog of the protein from the related speciesT. vincentiiwas used as a surrogate. This protein, Tv2483, was crystallized, resulting in the determination of its crystal structure at a resolution of 1.75 Å. The protein has a typical fold for a ligand-binding protein, and a single molecule of L-arginine was bound between its two lobes. Differential scanning fluorimetry and isothermal titration calorimetry experiments confirmed that L-arginine bound to the protein with unusually high selectivity. However, further comparison to Tp0309 showed differences in key amino-acid-binding residues may impart an alternate specificity for theT. pallidumprotein.

A head-activator binding protein is present in hydra in a soluble and a membrane-anchored form

Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4077-4086 ◽  
Author(s):  
W. Hampe ◽  
J. Urny ◽  
I. Franke ◽  
S.A. Hoffmeister-Ullerich ◽  
D. Herrmann ◽  
...  
Keyword(s):  
Stem Cells ◽  
Amino Acid ◽  
Transmembrane Domain ◽  
Binding Protein ◽  
Amino Acid Sequences ◽  
Secreted Protein ◽  
Specific Antibodies ◽  
Head Activator ◽  
Carboxy Terminal

The neuropeptide head activator plays an important role for proliferation and determination of stem cells in hydra. By affinity chromatography a 200 kDa head-activator binding protein, HAB, was isolated from the multiheaded mutant of Chlorohydra viridissima. Partial amino acid sequences were used to clone the HAB cDNA which coded for a receptor with a unique alignment of extracellular modules, a transmembrane domain, and a short carboxy-terminal cytoplasmic tail. A mammalian HAB homologue with identical alignment of these modules is expressed early in brain development. Specific antibodies revealed the presence of HAB in hydra as a transmembrane receptor, but also as secreted protein, both capable of binding head activator. Secretion of HAB during regeneration and expression in regions of high determination potential hint at a role for HAB in regulating the concentration and range of action of head activator.

scholarly journals Diversity of β-Lactam Resistance-Conferring Amino Acid Substitutions in Penicillin-Binding Protein 3 of Haemophilus influenzae

2002 ◽  
Vol 46 (7) ◽  
pp. 2208-2218 ◽  
Author(s):  
Henri Dabernat ◽  
Catherine Delmas ◽  
Martine Seguy ◽  
Roseline Pelissier ◽  
Genevieve Faucon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Haemophilus Influenzae ◽  
Binding Protein ◽  
Amino Acid Substitutions ◽  
Penicillin Binding Protein ◽  
Gene Encoding ◽  
Peptidoglycan Synthesis ◽  
Group I ◽  
Adults And Children

ABSTRACT The sequences of the ftsI gene, encoding the transpeptidase domain of penicillin binding protein (PBP) 3A and/or PBP 3B, which are involved in septal peptidoglycan synthesis, were determined for 108 clinical strains of Haemophilus influenzae with reduced susceptibility to β-lactam antibiotics with or without β-lactamase production and were compared to those of the ampicillin-susceptible Rd strain and ampicillin-susceptible clinical isolates. The sequences have 18 different mutation patterns and were classified into two groups on the basis of amino acid substitutions deduced from the nucleotide sequences located between bp 960 and 1618 of the ftsI gene. In group I strains (n = 7), His-517 was substituted for Arg-517. In group II strains (n = 101), Lys-526 was substituted for Asn-526. In subgroup IIa (n = 5; H. influenzae ATCC 49247), the only observed substitution was Lys-526 for Asn-526; in subgroup IIb (n = 56), Val-502 was substituted for Ala-502 (n = 13), along with several other substitutions: Asn-350 for Asp-350 (n = 15), Asn-350 for Asp-350 and Glu-490 for Gly-490 (n = 14), and Asn-350 for Asp-350 and Ser-437 for Ala-437 (n = 5). In subgroup IIc (n = 25), Thr-502 was substituted for Ala-502. In subgroup IId, Val-449 was substituted for Ile-449 (n = 15). The MICs of β-lactam antibiotics for the 108 strains were to 8 to 16 times the MICs for susceptible strains. The strains, isolated from both adults and children, were analyzed for genetic relationship by pulsed-field gel electrophoresis and by determination of ftsI sequence phylogeny. Both analyses revealed the lack of clonality and the heterogeneity of the strains, but some clusters suggest the spread and/or persistence of a limited number of strains of the same pulsotype and pattern of amino acid substitutions. Reduced susceptibility to β-lactam, brought about by mutations of the ftsI gene, is becoming a frequent phenomenon, affecting both strains that produce β-lactamase and those that do not. The level of resistance remains low but opens the way to greater resistance in the future.

scholarly journals Amino acid sequence of acyl-CoA-binding protein from cow liver

1987 ◽  
Vol 245 (3) ◽  
pp. 857-861 ◽  
Author(s):  
J Mikkelsen ◽  
P Højrup ◽  
P F Nielsen ◽  
P Roepstorff ◽  
J Knudsen
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Gas Phase ◽  
Fast Atom Bombardment ◽  
Binding Protein ◽  
Bovine Liver ◽  
Plasma Desorption ◽  
Flight Mass Spectrometry

Acyl-CoA-binding protein from bovine liver was purified with the use of reverse-phase h.p.l.c. in the final step. The complete amino acid sequence was determined by using a combination of gas-phase Edman degradation and electron-impact and fast-atom-bombardment mass spectrometry. The sequence was confirmed by determination of the Mr by plasma-desorption time-of-flight mass spectrometry.

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