Search results for "binding"

Mapping of the high molecular weight kininogen binding site of prekallikrein. Evidence for a discontinuous epitope formed by distinct segments of the…

1993

Prekallikrein, a glycoprotein involved in contact phase activation, circulates in plasma in the form of a binary complex with high molecular weight kininogen (H-kininogen). The binding to H-kininogen is mediated by the prekallikrein heavy chain consisting of four repetitive domains, A1-A4. To define more precisely the region(s) involved in kininogen binding, we have employed an affinity cross-linking strategy with a synthetic peptide of 31 residues which mimics the prekallikrein binding site of H-kininogen. Cross-linking of the radiolabeled peptide to (pre)kallikrein revealed a binding segment in the NH2-terminal portion of the prekallikrein heavy chain; another binding segment was located …

Mapping of the Discontinuous H-kininogen Binding Site of Plasma Prekallikrein

1999

Plasma prekallikrein, a zymogen of the contact phase system, circulates in plasma as heterodimeric complex with H-kininogen. The binding is mediated by the prekallikrein heavy chain consisting of four apple domains, A1 to A4, to which H-kininogen binds with high specificity and affinity (K(D) = 1.2 x 10(-8) M). Previous work had demonstrated that a discontinuous kininogen-binding site is formed by a proximal part located in A1, a distal part exposed by A4, and other yet unidentified portion(s) of the kallikrein heavy chain. To detect relevant binding segment(s) we recombinantly expressed single apple domains and found a rank order of binding affinity for kininogen of A2 > A4 approximately A…

Human kininogens interact with M protein, a bacterial surface protein and virulence determinant.

1995

Streptococcus pyogenes, the most significant streptococcal species in clinical medicine, expresses surface proteins with affinity for several human plasma proteins. Here we report that kininogens, the precursors to the vasoactive kinins, bind to the surface of S. pyogenes. M protein, a surface molecule and a major virulence factor-in these bacteria, occurs in > 80 different serotypes. Among 49 strains of S. pyogenes, all of different M serotypes, 41 bound radiolabelled kininogens, whereas 6 M protein-negative mutant strains showed no affinity. M protein of most serotypes bind fibrinogen, and among the 55 strains tested, binding of kininogens was closely correlated to fibrinogen bindi…

Mapping of the Discontinuous Kininogen Binding Site of Prekallikrein

1996

Prekallikrein, the precursor to the serine proteinase kallikrein, circulates in plasma in an equimolar complex with H-kininogen. The binding to H-kininogen is mediated by the kallikrein heavy chain consisting of four "apple" domains, A1-A4, which attaches to H-kininogen with high specificity and affinity (KD = 83 nM). At least two distinct portions of the kallikrein heavy chain form this H-kininogen binding site: a proximal segment located in the NH2-terminal fragment of the heavy chain encompassing A1, and distal segment(s) located in COOH-terminal fragment spanning domains A2-A4. The proximal binding segment has been located to amino acid positions 56-86 of A1. To precisely map the distal…

Isolation and Characterization of the Kininogen-binding Protein p33 from Endothelial Cells

1996

Abstract Kininogens, the precursor proteins of the vasoactive kinins, bind specifically, reversibly, and saturably to platelets, neutrophils, and endothelial cells. Two domains of the kininogens expose major cell binding sites: domain D3 that is shared by H- and L-kininogen and domain D5H that is exclusively present in H-kininogen. Previously we have mapped the kininogen cell binding sites to 27 residues of D3 (“LDC27”) and 20 residues of D5H (“HKH20”), respectively (Herwald, H., Hasan, A. A. K., Godovac-Zimmermann, J., Schmaier, A. H., and Muller-Esterl, W. (1995) J. Biol. Chem. 270, 14634-14642; Hasan, A. A. K., Cines, D. B., Herwald, H., Schmaier, A. H., and Muller-Esterl, W. (1995) J. B…

Kininogen binding protein p33/gC1qR is localized in the vesicular fraction of endothelial cells

1996

AbstractThe endothelial protein p33/gC1qR is thought to mediate the assembly of components of the kinin-forming and complement-activating pathways on the surface of cardiovascular cells. FACS analysis of intact human umbilical vein endothelial cells using specific antibodies to p33 revealed a minor fluorescence on the cell surface whereas permeabilized cells showed a bright fluorescence indicative of an intracellular localization of p33. Immunostaining of fixed cells confirmed the predominant intracellular localization of p33. Fractionation studies demonstrated that the vesicular but not the membrane fraction of EA.hy926 cells is rich in p33. We conclude that externalization of p33 must pre…

Small-sized platinum nanoparticles in soil organic matter: Influence on water holding capacity, evaporation and structural rigidity

2019

Abstract Engineered and anthropogenic nanoparticles represent a new type of pollutants. Up until now, many studies have reported its adverse effect on biota, but the potential influence on the properties and functions of environmental compartments has largely been ignored. In this work, the effect of Pt nanoparticles on the functions and properties of model soil organic matter has been studied. Using differential scanning calorimetry and molecular modeling, the effect of a wide range of 3 nm Pt nanoparticles concentrations on water holding capacity, the strength of water binding, the stability of water molecule bridges and the content of aliphatic crystallites was studied. It was found that…

PEP-19 and LPI camstatins are RNA-binding proteins

2010

The stem rust resistance gene Rpg5 encodes a protein with nucleotide-binding-site, leucine-rich, and protein kinase domains

2008

We isolated the barley stem rust resistance genes Rpg5 and rpg4 by map-based cloning. These genes are colocalized on a 70-kb genomic region that was delimited by recombination. The Rpg5 gene consists of an unusual structure encoding three typical plant disease resistance protein domains: nucleotide-binding site, leucine-rich repeat, and serine threonine protein kinase. The predicted RPG5 protein has two putative transmembrane sites possibly involved in membrane binding. The gene is expressed at low but detectable levels. Posttranscriptional gene silencing using VIGS resulted in a compatible reaction with a normally incompatible stem rust pathogen. Allele sequencing also validated the candi…

BIO Bragg gratings on microfibers for label-free biosensing

2021

[EN] Discovering nanoscale phenomena to sense biorecognition events introduces new perspectives to exploit nano science and nanotechnology for bioanalytical purposes. Here we present Bio Bragg Gratings (BBGs), a novel biosensing approach that consists of diffractive structures of protein bioreceptors patterned on the surface of optical waveguides, and tailored to transduce the magnitude of biorecognition assays into the intensity of single peaks in the reflection spectrum. This work addresses the design, fabrication, and optimization of this system by both theoretical and experimental studies to explore the fundamental physicochemical parameters involved. Functional biomolecular gratings ar…