Cross-linking study on skeletal muscle actin: interaction of suberimidate-treated actin with deoxyribonuclease I.
We have recently reported that actin modified with dimethyl suberimidate takes a filamentous form even under depolymerizing conditions, and this phenomenon is accounted for by the conformational fixation caused by the introduction of an intramolecular cross-link (Ohara, O., Takahashi, S., Ooi, T., & Fujiyoshi, Y. (1982) J. Biochem. 91, 1999-2012). The suberimidate-treated actin (SA) is not immediately depolymerized by deoxyribonuclease I (DNase I) but is depolymerized after incubation for one day, i.e., depolymerization is much slower than that for intact F-actin. The results on circular dichroic spectra of a mixture of SA and DNase I suggest that DNase I flips the conformation of SA into a G-actin-like state from the F-actin-like one when a tight SA-DNase I complex is formed. The suberimidate cross-link introduced in an SA molecule does not completely prevent the conformational change from the F-state to the G-state but stabilizes the actin conformation very greatly in the F-state.
D000199:Actins; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002942:Circular Dichroism; D003432:Cross-Linking Reagents; D003599:Cytoskeleton; D003851:Deoxyribonucleases; D004120:Dimethyl Suberimidate; D046911:Macromolecular Substances; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits
D000199:Actins; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D004120:Dimethyl Suberimidate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D003851:Deoxyribonucleases