caa a22 4500 397555849 CHVBK 20180308164801.0 cr unu---uuuuu 161202e199601 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021216 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021216 Conformational Change Precedes the Formation of Multimeric Fibronectin [Elektronische Daten] [Keiko Sakai, Tadahiko Fujii, Toshihiko Hayashi] Plasma fibronectin incubated with a low concentration of SH reagent under physiological conditions without cells formed a multimer which retained the ability of heparin-binding and cell-binding but lost gelatin affinity [Sakai, K., Fujii, T., and Hayashi, T. (1994) J. Biochem. 115, 415-421]. The conformation of the multimeric fibronectin, as observed by ultraviolet circular dichroism and fluorescence spectroscopy was different from that of dimeric plasma fibronectin. Monitoring the change in ellipticity indicated that conformational change was mostly accomplished within the first 3 h of incubation with 0.5 mM dithiothreitol at 37°C. In contrast, multimers became detectable after 4 h of incubation. The results indicate that the overall reaction of multimerization of plasma fibronectin consists of two steps: the initial step of conformational change of dimeric fibronectin, and the later polymerization step of the polypeptide in an altered conformation. The initial step, involving the conformational change of fibronectin, depended on temperature: it proceeded at 37°C but not at 25°C. In contrast the second step took place at 25°C at a low, yet significant rate. Proteolytic susceptibility of the fibronectin to thermolysin or m-calpain changed within 3 h of incubation with dithiothreitol at 37°C in accordance with the conformational change detected by circular dichroism. Namely, the fibronectin in an altered conformation appeared to be less susceptible to thermolysin, but more susceptible to m-calpain. The changes in enzymatic susceptibilities tended to be localized in the amino- and car boxy 1-terminal regions, which are consistent with the implications from the spectroscopic analysis. © by the Journal of Biochemistry Regular Papers nationallicence conformation nationallicence disulfide-bond nationallicence fibronectin nationallicence multimerization nationallicence Sakai Keiko Nippi Research Institute of Biomatrix 1-1 Senju-midoricho, Adachi-ku, Tokyo 120 aut Fujii Tadahiko Nippi Research Institute of Biomatrix 1-1 Senju-midoricho, Adachi-ku, Tokyo 120 aut Hayashi Toshihiko Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo Meguro-ku, Tokyo 153 aut The Journal of Biochemistry Oxford University Press 119/1(1996-01), 58-62 0021-924X 119:1<58 1996 119 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021216 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021216 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Sakai Keiko Nippi Research Institute of Biomatrix 1-1 Senju-midoricho, Adachi-ku, Tokyo 120 aut NATIONALLICENCE 700 1- Fujii Tadahiko Nippi Research Institute of Biomatrix 1-1 Senju-midoricho, Adachi-ku, Tokyo 120 aut NATIONALLICENCE 700 1- Hayashi Toshihiko Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo Meguro-ku, Tokyo 153 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 119/1(1996-01), 58-62 0021-924X 119:1<58 1996 119 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford