Photocross-linking from dinitrophenylated SH1 in myosin head. II. Cross-linked site on 50-kDa fragment.
We reported in the preceding paper [Muno, D., et al. (1987) J. Biochem. 101, 661-669] that the dinitrophenyl group exclusively introduced to SH1 on the 20-kDa fragment of myosin subfragment 1 was cross-linked to the 50-kDa fragment by irradiation, and that limited trypsinolysis of the cross-linked S1 generated an 83-kDa peptide, a cross-linking product between the 20- and 50-kDa fragments. This paper will deal with the location of the cross-linked residue on the 50-kDa fragment. When the 83-kDa fragment labeled at SH2 with a fluorogenic SH reagent was subjected to bromocyanolysis, a main fluorescent band, which implied a cross-linked peptide, appeared in the position with an apparent molecular mass of 18.5-kDa on SDS-PAGE. On the other hand, another cross-linked peptide was obtained from a complete tryptic digest of a 83-kDa fragment rich fraction. Amino acid sequence analysis of the two cross-linked peptides revealed that the DNP moiety attached at SH1 was cross-linked with a residue in the segment of the heavy chain spanning the 485-493 region from the N-terminus of the heavy chain.
Muno
D
D
Department of Biochemistry, School of Medicine, Juntendo University, Tokyo.
Sekine
T
T
D000595:Amino Acid Sequence; D003488:Cyanogen Bromide; D004591:Electrophoresis, Polyacrylamide Gel; D008970:Molecular Weight; D009218:Myosins; D010455:Peptides / Q000302:isolation & purification; D010782:Photolysis; D013438:Sulfhydryl Compounds; D014357:Trypsin / Q000378:metabolism
D010455:Peptides; D013438:Sulfhydryl Compounds; D014357:Trypsin; D009218:Myosins; D003488:Cyanogen Bromide