Nondenaturing two-dimensional electrophoretic analysis of loop-sheet polymerization of serpin, squamous cell carcinoma antigen-2

✍ Scribed by Shugo Nawata; Yoshinori Suminami; Hiroshi Hirakawa; Akihiro Murakami; Hidenobu Ogata; Fumitaka Numa; Masanori Fujimoto; Tatehiko Tanaka; Kazuyuki Nakamura; Hiroshi Kato

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 258 KB
• Volume: 22
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/1522-2683(200101)22:1<161::aid-elps161>3.0.co;2-x

✦ Synopsis

Two homologous serine proteinase inhibitors (serpins), squamous cell carcinoma (SCC) antigen-1 and -2 were separated by nondenaturing two-dimensional electrophoresis combined with immunostaining to acquire further information on these proteins under physiological conditions. Polymers of SCC antigen-2 were detected in cytosolic extracts prepared from tumor tissues. The polymer formation of SCC antigen-2 was apparently decreased and the SCC antigen-2-synthetic peptide binary complexes were newly formed by the addition of synthetic peptide with sequences corresponding to residues from P14 to P2 in the reactive center loop of SCC antigen-2. On the other hand, the incubation with synthetic peptides having the sequence of the reactive center loop of SCC antigen-1 or antithrombin had no effect on polymerization of SCC antigen-2. These data suggest that the polymerization of SCC antigen-2 may occur spontaneously in vivo by the loop-sheet mechanism of serpin.