TY - JOUR AU - KUWANO,, Yuh AB - Abstract When whole muscle fibers or myofibrils of rabbit and chicken skeletal muscles are directly solubilized in hot SDS solution, a very high molecular protein called titin can be isolated by gel filtration (Wang et al. 1979). Connectin, an elastic protein of muscle (Maruyama et al. 1977), can be isolated by a similar method from thoroughly extracted muscle residues. Studies of electrophoretic mobility on 2–3% polyacrylamide gel electrophoresis, amino acid composition, and localization in myofibrils determined by the indirect immunofluorescence technique showed that titin and connectin are identical. Connectin was found to be unstable in SDS solution on storage for a few days at room temperature; the doublet band of connectin on SDS gel electrophoresis became diffuse and eventually disappeared. Connectin was concentrated around the A-I junction region of a myofibril, although it was present in an entire sarcomere except for the Z lines. On removal of myosin, the A-I junction was still fluorescent, when treated with fluorescent antibody against connectin. In the KI-extracted myofibril, materials accumulated on both sides of the Z lines were strongly stained, and there were fluorescent filaments between the neighboring Z lines, but the Z lines were not stained at all. This content is only available as a PDF. Author notes 1 This work was supported by grants from the Ministry of Education, Science and Culture, the Ministry of Health and Welfare, the Yamada Science Foundation, and the Muscular Dystrophy Association. © 1981, by the Japanese Biochemical Society TI - Connectin, an Elastic Protein of Muscle. Identification of “Titin” with Connectin JF - The Journal of Biochemistry DO - 10.1093/oxfordjournals.jbchem.a133249 DA - 1981-01-01 UR - https://www.deepdyve.com/lp/oxford-university-press/connectin-an-elastic-protein-of-muscle-identification-of-titin-with-4tw02InBI2 SP - 701 EP - 709 VL - 89 IS - 3 DP - DeepDyve ER -