Search results for "Kininogen"

Analysis of cold activation of the contact system in hereditary angioedema with normal C1 inhibitor.

2021

Hereditary angioedema (HAE) attacks are caused by excessive activation of the contact system. Understanding how the contact system is activated in HAE, especially in patients with normal C1 inhibitor (HAEnCI), is essential to effectively treat this disease. Contact system activation involves the cleavage of several proteins including Factor XII (FXII), high molecular weight kininogen (HK), prekallikrein, sgp120 (ITIH4) and C1 inhibitor (C1-INH) before the subsequent generation of bradykinin that mediates HAE. In this study, we evaluated the fragmentation and enzymatic activity of contact system proteins in HAEnCI plasma samples before and after contact system activation induced by incubatio…

Parallel reduction of plasma levels of high and low molecular weight kininogen in patients with cirrhosis

1999

SummaryLittle is known about the regulation of high-molecular-weight-kininogen (HK) and low-molecular-weight-kininogen (LK) or the relationship of each to the degree of liver function impairment in patients with cirrhosis. In this study, we evaluated HK and LK quantitatively by a recently described particle concentration fluorescence immunoassay (PCFIA) and qualitatively by SDS PAGE and immunoblotting analyses in plasma from 33 patients with cirrhosis presenting various degrees of impairment of liver function. Thirty-three healthy subjects served as normal controls. Patients with cirrhosis had significantly lower plasma levels of HK (median 49 μg/ml [range 22-99 μg/ml]) and LK (58 μg/ml [15…

Assembly of human contact phase proteins and release of bradykinin at the surface of curli-expressing Escherichia coli.

1996

Previous work has demonstrated that most strains of the human pathogen Streptococcus pyogenes bind kininogens through M protein, a fibrous surface protein and virulence determinant. Here we find that strains of several other pathogenic bacterial species, both Gram-positive and Gram-negative, isolated from patients with sepsis, also bind kininogens, especially kininogen (HK). The most pronounced interaction was seen between HK and Escherichia coli. Among clinical isolates of E. coli, the majority of the enterohaemorrhagic, enterotoxigenic, and sepsis strains, but none of the enteroinvasive and enteropathogenic strains, bound HK. Binding of HK to E. coli correlated with the expression of curl…

Mapping the cell binding site on high molecular weight kininogen domain 5.

1995

Investigations mapped the region(s) on the light chain of high molecular weight kininogen (HK) that participates in cell binding. Sequential and overlapping peptides of domain 5 (D5H) were synthesized to determine its cell binding site(s). Three peptides from non-overlapping regions on D5H were found to inhibit biotin-HK binding to endothelial cells. Peptides GKE19 and HNL 21 weakly inhibited biotin-HK binding with IC50 of 792 and 215 microM, respectively. Peptide HKH20 inhibited biotin-HK binding with an IC50 of 0.2 microM. Two peptides, GGH18 and HVL24, which overlapped HKH20, also inhibited biotin-HK binding to endothelial cells with IC50 values of 108 and 0.8 microM, respectively. Bioti…

Hereditary angioedema cosegregating with a novel kininogen 1 gene mutation changing the N‐terminal cleavage site of bradykinin

2019

The Expanding Spectrum of Mutations in Hereditary Angioedema.

2021

The evolution in the knowledge of rare genetic diseases such as hereditary angioedema (HAE) has increased at a parallel pace with the development of new molecular tools. The deficiency of C1 inhibitor (C1-INH) has been recognized as the main cause of HAE (HAE-C1-INH) since the 1960s, but the discovery of the wide spectrum of mutations affecting the C1-INH gene (SERPING1) was possible only from the late 1980s, when Sanger sequencing became available and more accessible worldwide. Nevertheless, the involvement of other genes in HAE was discovered only in 2006 with the description of mutations in the F12 gene in patients with HAE and normal C1-INH. In the last 3 years, advanced next-generation…

Identification of an endothelial cell binding site on kininogen domain D3

1995

High and low molecular mass kininogen, two multidomain plasma proteins, bind to endothelial cells, platelets, and neutrophils in the intravascular compartment. The specific cell attachment site on their common heavy chain is mediated by domain-3, a cystatin-like structure with inhibitory capacity for papain-like proteinases (Jiang, Y., Müller-Esterl, W., and Schmaier, A. H. (1992) J. Biol. Chem. 267, 3712-3717). In this report, the domain-3 cell binding site is determined by an antibody-directed strategy. The epitope of monoclonal antibody HKH15, which binds to domain-3 and blocks the binding of kininogens to platelets and endothelial cells, was mapped using seven synthetic peptides, which …

Mapping of the H-Kininogen Binding Site Exposed by the Prekallikrein Heavy Chain

1992

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…