Modelling muscle motor conformations using low-angle X-ray diffraction

Squire, John M., AL-Khayat, Hind A., Harford, Jeffrey J., Hudson, Liam, Irving, Thomas C., Knupp, Carlo ORCID: https://orcid.org/0000-0001-9127-2252 and Reedy, Michael K. 2003. Modelling muscle motor conformations using low-angle X-ray diffraction. IEE Proceedings -Nanobiotechnology 150 (3) , pp. 103-110. 10.1049/ip-nbt:20031094

PDF Download (0B)

Abstract

New results on myosin head organization using analysis of low-angle X-ray diffraction patterns from relaxed insect flight muscle (IFM) from a giant waterbug,bu ilding on previous studies of myosin filaments in bony fish skeletal muscle (BFM),show that the information content of such low-angle diffraction patterns is very high despite the 'crystallographically low' resolution limit (65A( ) of the spacings of the Bragg diffraction peaks being used. This high information content and high structural sensitivity arises because: (i) the atomic structures of the domains of the myosin head are known from protein crystallography; and (ii) myosin head action appears to consist mainly of pivoting between domains which themselves stay rather constant in structure; thus (iii) the intensity distribution among diffraction peaks in even the low resolution diffraction pattern is highly determined by the high-resolution distribution of atomically modelled domain mass. A single model was selected among 5000+ computer-generated variations as giving the best fit for the 65 reflections recorded within the selected resolution limit of 65A( . Clear evidence for a change in shape of the insect flight muscle myosin motor between the resting (probably like the prepowerstroke) state and the rigor state (considered to mimic the end-of-powerstroke conformation) has been obtained. This illustrates the power of the low-angle X-ray diffraction method. The implications of these new results about myosin motor action during muscle contraction are discussed.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Optometry and Vision Sciences
Subjects:	R Medicine > RE Ophthalmology
Uncontrolled Keywords:	Low-angle X-ray diffraction ; Myosin
Publisher:	Institution of Engineering and Technology
ISSN:	1478-1581
Last Modified:	17 Oct 2022 09:41
URI:	https://orca.cardiff.ac.uk/id/eprint/5157

Citation Data

Cited 7 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item