title: [Structural changes in muscle fiber contractile proteins studied by polarization ultraviolet fluorescence microscopy. VI. Conformational restructurings of F-actin induced by the binding of heavy meromyosin].
abstract: Decrease in tryptophan fluorescence anisotropy of a single ghost muscle fibre was found at the binding of heavy meromyosin (HMM) to actin. Polarized fluorescence revealed its peak changes at a molar ratio of HMM/actin equal to 0.1. The changes observed in polarized fluorescence at F-actin-HMM interaction were found to depend on the state of HMM. The changes in anisotropy fluorescence under the same conditions were assumed to be independent of tryptophane residues in HMM, reflecting cooperative changes in F-actin conformation. Changes in the conformation of F-actin are of great importance in muscular contraction.
mesh_terms: D000199:Actins / Q000032:analysis* / Q000378:metabolism; D000818:Animals; D005454:Fluorescence Polarization; D066298:In Vitro Techniques; D008856:Microscopy, Fluorescence; D008859:Microscopy, Polarization; D008860:Microscopy, Ultraviolet; D009119:Muscle Contraction; D009124:Muscle Proteins / Q000032:analysis* / Q000378:metabolism; D009132:Muscles / Q000378:metabolism*; D015879:Myosin Subfragments / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D011817:Rabbits
chemical_list: D000199:Actins; D009124:Muscle Proteins; D015879:Myosin Subfragments
vernacular_title: Izuchenie strukturnykh izmeneniĭ sokratitel'nykh belkov myshechnogo volokna s pomoshch'iu poliarizatsionnoĭ ul'trafioletovŏi fluorestsentnoi mikroskopii. VI. Konformatsionnye perestroĭki F-aktina, indutsirovannye sviazyvaniem tiazhelogo meromiozina.