Tropomyosin protein, features

Tropomyosin is a two-stranded, o-helical coiled-coil molecule that aggregates head-to-tail with others to form long filamentous ropes. These lie in each of the two long period grooves of the actin microfilaments where, in vertebrate skeletal muscle, they play an important part in the Ca2+-mediated regulation of actin via troponin (a tropomyosin-associated protein). An important feature of tropomyosin is its 39.2-residue period— that is also quasi-halved (19.6 residues)—in the linear distribution of the acidic residues and, to a lesser extent, the apolar residues (McLachlan and Stewart, 1976 Parry, 1975). The number of residues in tropomyosin (284 residues), and the head-to-tail overlap (nine residues) that allows axial... 

A slow mover. Tropomyosin, a 93-kd muscle protein, sediments more slowly than does hemoglobin (65 kd). Their sedimentation coefficients are 2.6S and 4.3 IS, respectively. Which structural feature of tropomyosin accounts for its slow sedimentation ... 

Dyspnea, chest pain or syncope, usually features ventricular hypertrophy with impingement on LV volume and often LV outflow obstruction. Most cases hereditary, but some are new mutations. Defective genes for/3-MHC, either MLC, TnT, Tnl, a-tropomyosin, myosin binding protein C. 

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