Protein also known as:
Hepatocyte growth factor activator-like protein.
Cleaved into:
Hyaluronan-binding protein 2 27 kDa light chain; Hyaluronan-binding protein 2 27 kDa light chain alternate form; Hyaluronan-binding protein 2 50 kDa heavy chain; Hyaluronan-binding protein 2 50 kDa heavy chain alternate form.
Cleaves the alpha-chain at multiple sites and the beta-chain between 'Lys-53' and 'Lys-54' but not the gamma-chain of fibrinogen and therefore does not initiate the formation of the fibrin clot and does not cause the fibrinolysis directly. It does not cleave (activate) prothrombin and plasminogen but converts the inactive single chain urinary plasminogen activator (pro-urokinase) to the active two chain form. Activates coagulation factor VII.
A serine protease isolated from plasma sharing structural characteristics with a hepatocyte growth factor activator-like protease has been demonstrated recently to activate FVII. Accordingly, it was named 'FVII activator'. Until now an impact of this protease on the fibrinolytic system has not been reported. We islolated the protease from cryo-poor plasma by subsequent ion exchange chromatography and adsorption to immobilized heparin and/or aprotinin. Incubation of single-chain plasminogen activators (sc-PAs) with the FVII activator revealed significant activation of urokinase sc-PA (scu-PA) and tissue sc-PA (sct-PA) in vitro. It was enhanced in the presence of calcium and heparin. Compared to kallikrein, a more efficient activation of scu-PA was observed, whereas sct-PA appeared to be a poorer substrate for the FVI activator. At low protease concentrations and in the presence of heparin the scu-PA activation was comparable to plasmin. Employing recalcified whole blood thrombelastography, the lysis of initially formed fibrin was observed after addition of a combination of scu-PA and the FVII activator, whereas the scu-PA alone had a negligible effect at the concentration used. The study results as presented demonstrate that the FVII activator is a potent activator of sc-PAs in vitro. Whether it plays a physiological role in fibrinolysis deserves further investigation. Its comparatively high affinity to heparin assumes a function in cell surface or matrix events.
Plasma hyaluronan biding protein (PHBP) is a novel serine protease, which has an amino acid sequence homology to that of hepatocyte growth factor activator (HGFA), and has a similar domain structure to that of urinary plasminogen activator (u-PA), found in human plasma. We searched the PHBP substrate in human plasma by measuring the digested protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that fibrinogen and fibronectin were the major substrates of PHBP. PHBP cleaved the alpha-chain at multiple sites and the beta-chain between lysine53 and lysine54 but not the gamma-chain of fibrinogen. Therefore, PHBP did not initiate the formation of the fibrin clot and did not cause the fibrinolysis directly. PHBP did not cleave (activate) prothrombin and plasminogen, but it converted the inactive single chain urinary plasminogen activator to the active two chain form.
A novel hyaluronan-binding protein (PHBP) was purified from human plasma by affinity chromatography on hyaluronan-conjugated Sepharose. The contaminating IgM and albumin in the partially purified preparation were removed with anti-IgG antibody-conjugated Sepharose and anti-albumin antibody-conjugated Sepharose, respectively, and no other contaminant was observed. Finally, 800 micrograms of PHBP was isolated from 500 ml of human plasma. PHBP gave a single 70-kDa band on SDS-PAGE under non-reducing conditions, and 50-kDa and 17-kDa bands under reducing conditions. Thus, PHBP was a heterodimer composed of 50-kDa and 17-kDa subunits, bridged by a disulfide linkage. Both subunits had novel N-terminal amino acid sequences, indicating that PHBP was a novel hyaluronan-binding protein in human plasma. The amino acid sequence deduced from the nucleotide sequence of the cloned PHBP cDNA exhibited significant homology to that of hepatocyte growth factor activator (HGFA). The results of Northern blot analysis indicated that liver, kidney, and pancreas expressed PHBP mRNA. The predicted structure of PHBP showed three epidermal growth factor (EGF) domains, a kringle domain and a serine protease domain, from its N-terminus, although HGFA has a fibronectin type II domain, an EGF domain, a fibronectin type I domain, an EGF domain, a kringle domain, and a serine protease domain, from its N-terminus.
A novel hyaluronan-binding protein (PHBP) was purified from human plasma by affinity chromatography on hyaluronan-conjugated Sepharose. The contaminating IgM and albumin in the partially purified preparation were removed with anti-IgG antibody-conjugated Sepharose and anti-albumin antibody-conjugated Sepharose, respectively, and no other contaminant was observed. Finally, 800 micrograms of PHBP was isolated from 500 ml of human plasma. PHBP gave a single 70-kDa band on SDS-PAGE under non-reducing conditions, and 50-kDa and 17-kDa bands under reducing conditions. Thus, PHBP was a heterodimer composed of 50-kDa and 17-kDa subunits, bridged by a disulfide linkage. Both subunits had novel N-terminal amino acid sequences, indicating that PHBP was a novel hyaluronan-binding protein in human plasma. The amino acid sequence deduced from the nucleotide sequence of the cloned PHBP cDNA exhibited significant homology to that of hepatocyte growth factor activator (HGFA). The results of Northern blot analysis indicated that liver, kidney, and pancreas expressed PHBP mRNA. The predicted structure of PHBP showed three epidermal growth factor (EGF) domains, a kringle domain and a serine protease domain, from its N-terminus, although HGFA has a fibronectin type II domain, an EGF domain, a fibronectin type I domain, an EGF domain, a kringle domain, and a serine protease domain, from its N-terminus.
Catalysis of the hydrolysis of internal, alpha-peptide bonds in a polypeptide chain by a catalytic mechanism that involves a catalytic triad consisting of a serine nucleophile that is activated by a proton relay involving an acidic residue (e.g. aspartate or glutamate) and a basic residue (usually histidine).
A novel hyaluronan-binding protein (PHBP) was purified from human plasma by affinity chromatography on hyaluronan-conjugated Sepharose. The contaminating IgM and albumin in the partially purified preparation were removed with anti-IgG antibody-conjugated Sepharose and anti-albumin antibody-conjugated Sepharose, respectively, and no other contaminant was observed. Finally, 800 micrograms of PHBP was isolated from 500 ml of human plasma. PHBP gave a single 70-kDa band on SDS-PAGE under non-reducing conditions, and 50-kDa and 17-kDa bands under reducing conditions. Thus, PHBP was a heterodimer composed of 50-kDa and 17-kDa subunits, bridged by a disulfide linkage. Both subunits had novel N-terminal amino acid sequences, indicating that PHBP was a novel hyaluronan-binding protein in human plasma. The amino acid sequence deduced from the nucleotide sequence of the cloned PHBP cDNA exhibited significant homology to that of hepatocyte growth factor activator (HGFA). The results of Northern blot analysis indicated that liver, kidney, and pancreas expressed PHBP mRNA. The predicted structure of PHBP showed three epidermal growth factor (EGF) domains, a kringle domain and a serine protease domain, from its N-terminus, although HGFA has a fibronectin type II domain, an EGF domain, a fibronectin type I domain, an EGF domain, a kringle domain, and a serine protease domain, from its N-terminus.
Enzyme which catalyzes hydrolysis reaction, i.e. the addition of the hydrogen and hydroxyl ions of water to a molecule with its consequent splitting into two or more simpler molecules.
Proteolytic enzyme with a serine residue (Ser) in its active site. The reactivity of the serine residue is ensured by the vicinity of a histidine and an aspartate residue (catalytic triad), all three residues are required for the charge relay system to take place.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.