Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An important molecule in the activation of the complement system in vertebrates is factor B, a serine protease with a molecular mass of 95,000. Factor B and the complement component C2 are thought to have arisen by gene duplication. In mammals and in Xenopus the factor B gene is linked to the major histocompatibility complex (MHC), whereas in domestic fowl it segregates independently of the MHC. Here we describe the isolation of a cDNA clone coding for factor B in the zebrafish, Brachydanio rerio. The deduced protein sequence exhibits a characteristic mosaic structure consisting of the short consensus repeat (SCR), the von Willebrand factor, and the serine protease domains. The estimated time of factor B and C2 divergence (approximately 350 million years ago), combined with the fact that C2 has thus far been found only in mammals, suggest that the factor B-C2 gene duplication occurred after the divergence of mammal-like reptiles from other reptiles and hence also birds. After the duplication, the C2 component evolved significantly faster than factor B.
Mol Immunol 1996 Apr
PMID:A complement factor B-like cDNA clone from the zebrafish (Brachydanio rerio). 870 Jan 67

Acquired von Willebrand disease (vWD) has been described in a few patients with chronic myelocytic leukemia (CML). We present here acquired type 2 vWD associated with CML and provide characterization of an inhibitor to von Willebrand factor (vWF) from this patient. His bleeding time was prolonged. Ristocetin-induced platelet agglutination was abolished whereas botrocetin-mediated aggregation was normal. Multimeric analysis of vWF from patient's plasma showed that larger sizes of multimers were reduced. His past and family histories were negative for bleeding tendency. These results suggested that acquired type 2 vWD was present during his clinical course. The inhibitor was purified by Staphylococcal protein A, suggesting an IgG antibody. Both binding of 125I-vWF to GPIb and platelet agglutination by ristocetin were inhibited by the patient IgG with the concentrations of competing substances necessary to inhibit specific binding by 50% (IC50s) of 260 micrograms/ml and 420 micrograms/ml, respectively. However, the IgG had no effect on these studies mediated by botrocetin. The IgG only reacted with intact vWF and a 39/34 kDa fragment of vWF. These results indicate that the recognition of GPIb binding site(s) on vWF by the IgG is a central pathogenesis of acquired type 2 vWD in this case.
Hematopathol Mol Hematol 1996
PMID:Acquired type 2A von Willebrand disease in chronic myelocytic leukemia. 887 31

The proprotein processing enzyme furin is the mammalian prototype of a novel family of subtilisin-like serine endoproteases which possess cleavage specificity for sites involving multiple basic amino acid residues and are involved in the processing of precursor proteins of a variety of regulatory peptides and proteins. One of the limiting steps in the engineering of mammalian cells designed for the overproduction of secreted proteins is the endoproteolytic cleavage of the precursor molecule to its mature biologically active form. The extremely low level of endogenous furin is likely the reason why cells are not able to fully mature overexpressed precursor proteins to their mature form. Here, we report a CHO-derived cell line genetically engineered for the production of high levels of recombinant proteins that need such endoproteolytic maturation. First, the human furin cDNA under the control of the cytomegalovirus early promoter and enhancer was introduced and overexpressed in a DHFR-deficient CHO cell line. A permanent cell line CHO-D3-FUR was established that expressed biologically active furin. Subsequently, to demonstrate the capacity of CHO-D3-FUR cells to produce recombinant proteins in a fully matured form, two derivative cell lines were established that overexpressed the von Willebrand factor (vWF) and transforming growth factor beta 1 (TGF beta 1); CHO-D3-vWF and CHO-D3-TGF beta 1, respectively. Both derivative cell lines were able to produce relatively high levels of recombinant protein in a fully matured and biologically active form. Our results illustrate the potential of the CHO-D3-FUR cell line in the production of recombinant secretory proteins that need endoproteolytic activation at the consensus furin cleavage sequence Arg-X-Lys/Arg-Arg.
Mol Biol Rep 1996
PMID:Production of recombinant proteins in Chinese hamster ovary cells overexpressing the subtilisin-like proprotein converting enzyme furin. 898 22

The ratiometric fluorescent indicators Fura-2 and Indo-1 are considered optimal probes for monitoring intracellular free calcium concentration ([Ca2+]i). Unique problems arise, however, in studying [Ca2+]i changes induced in platelets by von Willebrand factor (vWF). Binding of native multimeric vWF causes extensive platelet aggregation, and is reported to evoke a gradual [Ca2+]i increase. the present investigation examined the reliability of platelet [Ca2+]i measurements in these circumstances. Ristocetin-mediated binding of vWF to human platelets promoted a slow rise in Fura-2 fluorescence ratio. Fura-2 extrusion contributed substantially to this rise, unless blocked by probenecid. Despite this precaution, the platelets were invariably contaminated slightly with extracellular indicator. As aggregation progressively reduced the number of platelets in the spectrofluorometer beam, through settling of the larger aggregates, such extracellular Fura-2 contributed proportionately more to the observed fluorescence. This extraneous signal accounted completely for the fluorescence ratio increase, and apparent [Ca2+]i rise, in response to native multimeric vWF. The same problem arose with Indo-1, whereas the single wavelength indicator Fluo-3 showed the opposite pattern of apparent [Ca2+]i changes. Thus, none of these indicators provides reliable data on [Ca2+]i signals in aggregating platelets. Use of a dimeric form of vWF eliminated the problem of platelet aggregates settling out of suspension, but also virtually abolished the [Ca2+]i increase. These observations may explain some of the inconsistencies among previous investigations of vWF-induced calcium signaling. Moreover, similar problems may arise in studies with other adhesive proteins.
Blood Cells Mol Dis 1996
PMID:Fluorescent indicators give biased estimates of intracellular free calcium change in aggregating platelets: implication for studies with human von Willebrand factor. 907 74

A 328-bp sequence from exon 1 of the gene for aquaporin-2 (AQP2) was compared in 12 mammalian species, representing as many eutherian orders. This sequence encodes the N-terminal half of this kidney-specific water channel protein. Most amino acid replacements, as well as an insertion, have occurred in extracellular loops connecting the transmembrane helices, in agreement with a lower functional importance of these loops. Phylogenetic analyses were performed with parsimony, distance, and maximum-likelihood methods. The AQP2 data set, alone as well as in combination with previously published alpha A-crystallin protein sequences, strongly supports a clade consisting of elephant, hyrax, aardvark, and elephant shrew, reaching bootstrap values of 99%. This finding fully agrees with the only other presently available sequence data sets that include these taxa, those of von Willebrand factor and interphotoreceptor retinoid-binding protein, and suggests that this extended paenungulate clade is one of the most conspicuous superordinal groupings in eutherian phylogeny. Some support was obtained for an artiodactyl/perissodactyl clade, while the grouping of pholidotes with edentates was contradicted.
Mol Biol Evol 1997 Apr
PMID:Molecular evolution of mammalian aquaporin-2: further evidence that elephant shrew and aardvark join the paenungulate clade. 910 Mar 66

The bovine caseinoglycopeptide (residues 106-169), the C-terminal part of kappa-casein, inhibited the von Willebrand factor-dependent platelet aggregation in a dose-dependent manner. An affinity matrix made of the caseinoglycopeptide selectively bound the platelet membrane glycoprotein GPIb alpha which contains the von Willebrand factor binding site. The amino acid residues of GPIb alpha participating in the caseinoglycopeptide binding were located after residue Glu 90.
Biochem Mol Biol Int 1997 Jun
PMID:Binding of the bovine caseinoglycopeptide to the platelet membrane glycoprotein GPIb alpha. 919 87

We have solved the crystal structure of the Fab fragment of NMC-4, a mouse monoclonal antibody that binds to the A1 domain of von Willebrand factor (vWF). Two Asp and three Tyr residues in the complementarity determining regions 1 and 3 of the heavy chain exhibited a spatial orientation suggestive of a dominant role in establishing contact with the antigen. A cluster of Asp and Tyr residues occurs also in a region of the platelet glycoprotein (GP) Ib alpha amino terminal domain known to be critically involved in vWF binding. Thus, the structural information obtained with NMC-4 may prove relevant to understand the stereochemical bases of the GP Ib alpha-vWF interaction essential for thrombus formation at sites of vascular lesion.
Blood Cells Mol Dis 1997
PMID:Crystal structure of NMC-4 fab anti-von Willebrand factor A1 domain. 921 57

Recent studies have demonstrated the feasibility of cytokine gene transfer to enhance the antitumor activities of host immune cells. Endothelial cells forming the vascular supply of tumors may be useful vehicles for the delivery of cytokine molecules in order to effect tumor immunotherapy. In order to determine whether primary endothelial cells can express cytokine transgenes efficiently, we constructed two retroviral vectors containing a cDNA encoding either recombinant human interleukin-1 alpha (rhIL-1 alpha) or recombinant human interleukin-2 (rhIL-2), called LNCIL-1 alpha and LNCIL-2 respectively, and studied the expression of the two cytokines in vitro in non-immortalized endothelial cells. Human umbilical vein endothelial cells (HUVEC) transduced with LNCIL-1 alpha or LNCIL-2 secreted 1.8-33 ng/10(6) cells/24 h and 40-246.7 ng/10(6) cells/24 h of biological active rhIL-1 alpha and rhIL-2 respectively. Mouse microvascular endothelial cells (MMEC) transduced with LNCIL-1 alpha and LNCIL-2 secreted 1.5 ng/10(6) cells/24 h and 5.8-24.7 ng/10(6) of biologically active rhIL-1 alpha and rhIL-2 proteins respectively. Cocultivation of HUVEC/IL-2 and MMEC/IL-2 with normal human bone marrow cells generated potent cytotoxic activity against K562, Daudi and other cell targets in a 51Cr-release assay. While IL-2 transgene-expressing HUVEC and MMEC retained their normal morphology, rhIL-1 alpha transgene expression inhibited the growth and altered the morphology of both HUVEC and MMEC in culture. The cytokine-gene-transduced endothelial cells retained other endothelial cell features, including uptake of acetylated low-density lipoprotein (Ac-LDL) and expression of von Willebrand factor, and were euploid as shown by flow cytometry. These results demonstrate that endothelial cells, by sustaining the production of biologically active rhIL-2 at levels that are sufficient for the activation of potent cytotoxic lymphocyte activity, may be useful agents for cancer gene therapy.
Cytokines Mol Ther 1996 Jun
PMID:Towards endothelial-cell-directed cancer immunotherapy: in vitro expression of human recombinant cytokine genes by human and mouse primary endothelial cells. 938 93

A method for establishing primary cultures of smooth muscle cells (SMCs) from the porcine coronary artery without either microdissection and/or enzymatic dispersion was developed using selective migration of cells from coronary explants in vitro. This culture method relies on the heterogeneity of cell types and differences in their migration and adherence ability to separate SMC from contaminating fibroblasts or endothelial cells. The cell type was determined by immunohistochemical staining with monoclonal antibodies to SM alpha-actin, SM myosin, h-caldesmon and von Willebrand factor. The first wave of migration (1-7 days) consisted of a mixture of fibroblasts and SMCs. Only SMCs were present in the second wave of migration (7-14 days). Endothelial cells, which exhibited a lower capacity for migration and adherence, were restricted to the third wave of migration (14-21 days). Cells obtained from the second wave of migration exhibited the characteristic single-layered, aligned, hill-and-valley pattern of SMCs when confluent. Quiescence was attained 4-5 days after removal of serum, as established by [3H]-thymidine incorporation. Stimulation of the quiescent SMCs with 20% FBS resulted in a synchronous re-entry into the cell-cycle with S phase reached 15-18 h later. The SMCs prepared using this protocol thus exhibit the structural markers and capacity to undergo phenotypic modulation that are characteristic of SMCs in vivo. This approach to establishing primary cultures of SMCs offers the advantage of selecting for the subpopulation of cells capable of migration in response to injury or growth factor stimulation.
Mol Cell Biochem 1997 Nov
PMID:Coronary artery smooth muscle in culture: migration of heterogeneous cell populations from vessel wall. 940 45

We report the sequence of a 2,779 base pari genomic DNA fragment containing the mouse glycoprotein (GP) Ibalpha gene. Similar to its human counterpart, the mouse GP Ibalpha gene contains a single exon encoding a 734-residue GP Ibalpha precursor polypeptide. Comparative analysis between human and mouse polypeptides reveals a 75% sequence similarity between the amino-terminal domain of each polypeptide. However, there is sequence divergence within a short linear sequence of the amino-terminal domain previously implicated in human GP Ibalpha as critical for the binding of human von Willebrand factor (vWF). Mouse and human primary sequences diverge through their extracytoplasmic macroglycopeptide domains reducing the overall sequence similarity to 70%. The transmembrane and cytoplasmic sequences are highly conserved in both species with 59 identical residues among the 62 comprising the carboxyl-terminus of each polypeptide. The species-specific interaction between human GP Ibalpha and vWF was demonstrated in a model flow system monitoring the ability of surface-bound human vWF to capture from flowing blood normal mouse platelets or transgenic mouse platelets expressing the human GP Ibalpha subunit. The results further define the structural elements necessary for the interaction of human vWF and platelets.
Blood Cells Mol Dis 1997 Aug
PMID:Cloning of the murine platelet glycoprotein Ibalpha gene highlighting species-specific platelet adhesion. 941 Apr 73


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