Tropomyosin: a New Asymmetric Protein Component of Muscle

Bailey, Kenneth

doi:10.1038/157368b0

Cited by 116 publications

(43 citation statements)

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“…The phenomenon of globule-fibril transformation was of considerable interest to cell and molecular biologists ofthe time since it seemed to provide a clue to understanding the changing physical properties of cytoplasm. Related molecular properties had, during this early period ofelectron microscopic studies ofbiopolymers, also been described for insulin (4), actin (5), and tropomyosin (6). However, the conditions for fibril formation ofthese proteins are widely different from those of the protein described here.…”

Section: Introductionmentioning

confidence: 90%

Isolation, characterization, and distribution of an unusual pancreatic human secretory protein.

Gross¹,

Carlson²,

Brauer³

et al. 1985

J. Clin. Invest.

118

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An unusual protein was isolated from acid extracts of normal human pancreas and pancreatic secretion in the form of uniform 7-10-nm long single threads without visible axial periodicity or other structure, as seen in the electron microscope. It accounts for as much as 300 ,g/ml in some pancreatic secretions as measured by specific radioimmunoassay. The protein undergoes a freely reversible, pH dependent, globule-fibril transformation, being stable in the fibril form between pH 5.4 and 9.2. The monomer at acid pH has an apparent molecular weight of -14,000 and consists of a single polypeptide chain, the amino acid composition of which is rich in aromatic amino acids and lacks carbohydrate, fatty acid, and phosphate. the amino acid sequence of 45 residues from the amino terminus shows no homology with any other reported protein sequences other than that of the A chain of the bovine pancreas thread protein (reported elsewhere). A sensitive radioimmunoassay employing monoclonal antibodies against human pancreatic thread protein failed to detect the antigen in a wide range of human tissues other than pancreas, nor was the antigen measurable in normal human sera. Immunohistochemistry utilizing these antibodies revealed the antigen as a component of the cytoplasm of some but not all the pancreatic acinar cells. A physiologic function has not yet been determined for this protein.

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Section: Introductionmentioning

confidence: 90%

Isolation, characterization, and distribution of an unusual pancreatic human secretory protein.

Gross¹,

Carlson²,

Brauer³

et al. 1985

J. Clin. Invest.

118

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“…Here S 1 represents the myosin head, S 1 and S 2 comprise the cross-bridge, and LMM forms the bulk of the thick filament Tropomyosin, a thin filament-associated protein Tropomyosin (Tm) spans each seven actin monomers. It was discovered by Kenneth Bailey in 1946(Bailey 1946) who proposed that due to its Banalytical and structural similarities […] [tropomyosin] is a species of myosin differing mainly in the length of the polypeptide chain^and so Bin proposing the present name, we have deemed it desirable to retain the word 'myosin' and to add a prefix which suggests this specific relationship.^Today, tropomyosin is far from being a species of myosin. It has two parallel α-helical chains, overlapping head-to-tail along the thin filament.…”

Section: Actomyosin/cross-bridges and Atpmentioning

confidence: 99%

Historical perspective on heart function: the Frank–Starling Law

Sequeira

Velden

2015

Biophys Rev

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More than a century of research on the FrankStarling Law has significantly advanced our knowledge about the working heart. The Frank-Starling Law mandates that the heart is able to match cardiac ejection to the dynamic changes occurring in ventricular filling and thereby regulates ventricular contraction and ejection. Significant efforts have been attempted to identify a common fundamental basis for the Frank-Starling heart and, although a unifying idea has still to come forth, there is mounting evidence of a direct relationship between length changes in individual constituents (cardiomyocytes) and their sensitivity to Ca 2+ ions. As the Frank-Starling Law is a vital event for the healthy heart, it is of utmost importance to understand its mechanical basis in order to optimize and organize therapeutic strategies to rescue the failing human heart. The present review is a historic perspective on cardiac muscle function. We Brevive^a century of scientific research on the heart's fundamental protein constituents (contractile proteins), to their assemblies in the muscle (the sarcomeres), culminating in a thorough overview of the several synergistically events that compose the Frank-Starling mechanism. It is the authors' personal beliefs that much can be gained by understanding the Frank-Starling relationship at the cellular and whole organ level, so that we can finally, in this century, tackle the pathophysiologic mechanisms underlying heart failure.

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“…In the present paper, a new fibrillar protein of asymmetric character and relatively low molecular weight, quite distinct in all its major properties from actin, is described. A brief report of its isolation has already been published (Bailey, 1946a). Whilst the emphasis in considering th.e function both of adenosine triphosphatase and of actin has been upon their possible role in the contractile process, the properties of this newer component suggest that it is a prototype of the much larger myosin molecule and might conceivably be a unit utilized in the elaboration of myosin itself.…”

mentioning

confidence: 99%