o-Iodosobenzoic oxidation and cleavage of myosin subfragment 1.
1. o-Iodosobenzoic acid (IOB) caused the formation of a disulfide bridge between SH1 and SH2 groups of myosin SF1 rendering inactive its ATPase activity. 2. IOB at high concentrations provoked fragmentation of SF1 at its tryptophan residues. 3. The main fragmentation point was located at 15 K from the amino terminus of the myosin heavy chain. 4. Actin was not fragmented by IOB. It protected SF1 tryptophans from IOB attack. 5. These results suggest a possible use of IOB as a reagent to study protein tryptophan under nondenaturing conditions.
Longo
C
C
Department of Biochemistry, University of Navarra, Pamplona, Spain.
Garrido
B
B
Zalba
G
G
López-Moratalla
N
N
Santiago
E
E
D000199:Actins / Q000378:metabolism; D000818:Animals; D002645:Chickens; D004220:Disulfides / Q000032:analysis; D004229:Dithiothreitol / Q000494:pharmacology; D004586:Electrophoresis; D007463:Iodobenzoates / Q000494:pharmacology*; D007700:Kinetics; D015879:Myosin Subfragments / Q000378:metabolism; D009218:Myosins / Q000378:metabolism*; D010084:Oxidation-Reduction; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D014357:Trypsin
D000199:Actins; D004220:Disulfides; D007463:Iodobenzoates; D015879:Myosin Subfragments; D013439:Sulfhydryl Reagents; C008154:2-iodosobenzoic acid; D014357:Trypsin; D009218:Myosins; D004229:Dithiothreitol