Amino acid sequence of bovine heart coupling factor 6.

Publisher Website
Google Scholar
Abstract
The amino acid sequence of bovine heart mitochondrial coupling factor 6 (F6) was determined by automated Edman degradation of the whole protein and derived peptides. Preparations based on heat precipitation and ethanol extraction showed allotypic variation at 3 positions while material further purified high performance liquid chromatography yielded only 1 sequence that also differed by a Phe-Thr replacement at residue 62. The mature protein contains 76 amino acids with a calculated MW of 9006 and a pI [isoelectric point] of .apprxeq. 5, in good agreement with experimentally measured values. The charged amino acids are mainly clustered at the termini and in 1 section in the middle; these 3 polar segments are separated by 2 segments relatively rich in nonpolar residues. Chou-Fasman analysis suggests 3 stretches of .alpha.-helix coinciding (or within) the high-charge-density sequences with a single .beta.-turn at the 1st polar-nonpolar junction. Comparison of the F6 sequence with those of other proteins did not reveal any homologous structures.