title: Poorly understood aspects of striated muscle contraction.
abstract: Muscle contraction results from cyclic interactions between the contractile proteins myosin and actin, driven by the turnover of adenosine triphosphate (ATP). Despite intense studies, several molecular events in the contraction process are poorly understood, including the relationship between force-generation and phosphate-release in the ATP-turnover. Different aspects of the force-generating transition are reflected in the changes in tension development by muscle cells, myofibrils and single molecules upon changes in temperature, altered phosphate concentration, or length perturbations. It has been notoriously difficult to explain all these events within a given theoretical framework and to unequivocally correlate observed events with the atomic structures of the myosin motor. Other incompletely understood issues include the role of the two heads of myosin II and structural changes in the actin filaments as well as the importance of the three-dimensional order. We here review these issues in relation to controversies regarding basic physiological properties of striated muscle. We also briefly consider actomyosin mutation effects in cardiac and skeletal muscle function and the possibility to treat these defects by drugs.
authors.affiliation: Department of Chemistry Biomedical Sciences, Linnaeus University, 39182 Kalmar, Sweden.
authors.forename: Alf
authors.initials: A
authors.lastname: Månsson
authors.affiliation: Department of Kinesiology and Physical Education, McGill University, Montreal, QC, Canada H3A 2T5.
authors.forename: Dilson
authors.identifier: 0000-0001-7080-9364
authors.initials: D
authors.lastname: Rassier
authors.affiliation: Institute for Biophysical Chemistry, Medizinische Hochschule Hannover, 30625 Hannover, Germany.
authors.forename: Georgios
authors.identifier: 0000-0002-5161-4884
authors.initials: G
authors.lastname: Tsiavaliaris
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D006801:Humans; D009119:Muscle Contraction; D054792:Muscle, Striated / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D009218:Myosins / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D000199:Actins; D000255:Adenosine Triphosphate; D009218:Myosins