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Specific reassociation of the polypeptide subunit chains of helical myosin fragments
Author(s) -
Szilágyi L.,
Bálint M.,
Biró N.A.
Publication year - 1972
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(72)80125-x
Subject(s) - chemistry , protein subunit , combinatorics , mathematics , stereochemistry , microbiology and biotechnology , library science , biochemistry , biology , computer science , gene
A two-stranded rope twisted of 2 polypeptide chains in a-helical conformation is the generally accepted structural basis for most of the fibrous proteins of the a-type [l] . The cr-helices of synthetic polypeptides are in general single. The nature bringing about the multiple supercoil structure of the a-proteins is not completely understood. The different proteolytic fragments;of the fibrous part of the myosin molecule provide excellent objects for studying this problem. Up to the present time 7 fragments comprising different parts of the myosin “rod” are known (fig. 1). One of them, light meromyosin (LMM) was shown to be uncoiled and refolded to the original structure when solvent conditions are changed between denaturing and benign, respectively [2, 31. We have successfully extended these reversibility studies to the urea denaturation of 4 further fragments (LF1, LF-2, LF-3 and HMM-S-2). Carrying out the “renaturation” experiments with a mixture in urea of all 5 fragments (LMM plus the ones specified above) a surprising specificity according to length has been observed. No molecules consisting of a shorter and a longer chain were formed though a considerable part of the longer chains is identical in sequence with several kinds of shorter chains present (fig. 1).