Biomedical subjects

V V Bychkova

Publications and source records attributed to V V Bychkova.

5 recordsLinked to original sources

PubMed1996

Beta 1 integrin subunit dimerization via disulfide bonds.

Integrins of the beta 1 family were isolated from human smooth muscle. SDS-PAGE analysis and subsequent immunoblotting demonstrated that integrin samples contain a protein immunologically related to beta 1 integrin subunit with the previously undescribed apparent molecular mass 205 kD. One-dimensional peptide mapping showed that the 205 kD protein is not a novel beta 1 related integrin subunit, but a beta 1 integrin subunit dimer. After reduction the major part of the beta 1 immunoreactive material migrated from the 205 kD to 130 kD region, indicating that beta 1 integrin subunit dimers were formed via disulfide bonds. When electrophoretically pure beta 1 monomer and dimer forms were analized it was found that during SDS-PAGE about 30% of beta 1 integrin subunit monomers were organized into dimers while approximately 70% of the beta 1 dimer form was partly disrupted into monomers. It was suggested that this steady-state process is a result of a reversible reaction between intra- and intermolecular disulfide bonds. Possible in vivo dimerization of integrins via disulfide bonds is discussed.

Chromatography, Affinity↗

PubMedDate not supplied

[Isolation of fibronectin peptide fragments of various sizes and biological activity using affinity chromatography on an immobilized plasmin].

Plasmin, immobilized on Sepharose, was used for isolation of human blood plasma fibronectin fragments obtained after proteolysis. Under definite conditions the major part of the fibronectin fragments, liberated during proteolysis, remained to be bound to plasmin-Sepharose. As shown by electrophoretic analysis, the fraction of fragments bound to plasmin-Sepharose constituted mainly "heavy" (greater than or equal to 120 kD) peptides and one "light" (29 kD) peptide, while only "light" fragments (less than or equal to 45 kD) were detected in the free unbound fraction. These unbound to plasmin-Sepharose fibronectin fragments were found to stimulate proliferation of human embryonal fibroblasts in cell culture, whereas the plasmin-Sepharose bound peptides did not exhibit any effects on proliferation.

Cell Division↗

PubMedDate not supplied

[Isolation and purification of collagen proteins using biospecific chromatography on a sorbent with collagen-binding fragment of fibronectin].

A new procedure is described for isolation of collagens from various preparations containing small amounts of these proteins. The procedure is based on specific affinity of collagens of various types to one of peptide fragments of fibronectin--collagen-binding peptide (CBP). Collagens were isolated after single-step chromatography of tissue homogenate on the sorbent containing immobilized CBP. High specificity and reproducibility of the procedure was shown when various preparations were used: chicken embryo proteins with total radioactive label. Proteins synthesized in fibroblast culture; polypeptides synthesized in cell-free system of protein synthesis.

Animals↗

PubMedDate not supplied

[Characteristics of collagen preparations labelled in vitro by 14C-acetic anhydrides. Their use for the determination of collagenase activity and as radioactive markers].

A modified procedure in developed for acetylation by means of 14C-acetic anhydride of highly purified collagen I preparations. The acetylated collagen exhibited high specific radioactivity and was effectively hydrolyzed by bacterial collagenase. The 14C-acetylated collagen was used as a radioactive marker in electrophoretic analysis of labelled proteins.

Acetates↗

PubMedDate not supplied

[Electrophoretic characteristics of integrin++ beta1 subunit from human smooth muscles].

Total fraction of beta 1 integrin family was isolated from human smooth muscle by affinity chromatography on immobilized anti-beta 1 monoclonal antibodies. SDS-PAGE analysis and subsequent immunoblotting demonstrated that integrin samples contain unknown before high molecular mass (205 kD-nonreduced and 230 kD-reduced) material immunologically related to beta 1 integrin subunit. One dimensional peptide mapping showed that the 205 kD protein is not a novel beta 1 related integrin subunit, but a beta 1 integrin subunit dimer. Reduction of electrophoretic samples with dithiothreitol led to the removal of the major part of the beta 1 immunoreactive material from 205 kD to 130 kD region, indicating a disulfide nature of B1 integrin subunit dimer. The 230 kD protein turned out to be an only partly reduced beta 1 integrin disulfide bonded dimer. Possible in vivo existence of the disulfide bonded dimer and oligomer integrin forms is discussed.

Electrophoresis, Polyacrylamide Gel↗