Iodoacetic AcidIodoacetatesHydrocarbons, IodinatedIodoacetamideCysteineAlkylationGlycolysisDinitrophenolsSulfhydryl CompoundsDisulfidesHydrogen-Ion ConcentrationSulfhydryl ReagentsCyanidesKineticsDithiothreitolEndopeptidasesAmino AcidsEthylmaleimideAmino Acid SequenceMolecular WeightTrypsinAdenosine TriphosphateCysteine EndopeptidasesBinding SitesElectrophoresis, Polyacrylamide GelMolecular Sequence DataMusclesSubstrate Specificity