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Hugh E Huxley

Publications and source records attributed to Hugh E Huxley.

6 recordsLinked to original sources
PubMed2004

Recent X-ray diffraction studies of muscle contraction and their implications.

Recent studies on the interference fringes in the myosin meridional reflections provide a new source of structural information on cross-bridge movement during mechanical transients and steady shortening. Many observations can be interpreted satisfactorily by the tilting lever-arm model, with some assumptions, including the presence of fixed repeating structures contributing to the M3 and higher-order meridional reflections. In isometric contraction, the lever arms are oriented near the start of the working stroke, with a dispersion of ca+/-20-25 degrees . Upon a rapid release of 10-12 nm, they move to the end of the stroke, with a well-known T2 delay of 1-2 ms. This delay must represent additional processes, which have to occur even in tension-generating heads, or activation of attached heads, which initially do not develop force. Surprisingly, in muscles shortening at moderate loads (0.5-0.6 P0), the mean position of the heads moves only 2-3 nm closer to the M-line than in the isometric case, reminiscent of the Piazzesi-Lombardi model.

Animals↗
PubMed2004

Fifty years of muscle and the sliding filament hypothesis.

This review describes the early beginnings of X-ray diffraction work on muscle structure and the contraction mechanism in the MRC Unit in the Cavendish Laboratory, Cambridge, and later work in the MRC Molecular Biology Laboratory in Hills Road, Cambridge, where the author worked for many years, and elsewhere. The work has depended heavily on instrumentation development, for which the MRC laboratory had made excellent provision. The search for ever higher X-ray intensity for time-resolved studies led to the development of synchrotron radiation as an exceptionally powerful X-ray source. This led to the first direct evidence for cross-bridge tilting during force generation in muscle. Further improvements in technology have made it possible to study the fine structure of some of the X-ray reflections from contracting muscle during mechanical transients, and these are currently providing remarkable insights into the detailed mechanism of force development by myosin cross-bridges.

Actins↗