Erratum to: Identification of functional differences between recombinant human α and β cardiac myosin motors

Deacon, John C. and Bloemink, Marieke J. and Rezavandi, Heresh and Geeves, Michael A. and Leinwand, Leslie A. (2012) Erratum to: Identification of functional differences between recombinant human α and β cardiac myosin motors. Cellular and Molecular Life Sciences, 69 (24). pp. 4239-4255. ISSN 1420-682X. (doi:https://doi.org/10.1007/s00018-012-1111-5) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided. (Contact us about this Publication)
Official URL
http://dx.doi.org/10.1007/s00018-012-1111-5

Abstract

The myosin isoform composition of the heart is dynamic in health and disease and has been shown to affect contractile velocity and force generation. While different mammalian species express different proportions of α and β myosin heavy chain, healthy human heart ventricles express these isoforms in a ratio of about 1:9 (α:β) while failing human ventricles express no detectable α-myosin. We report here fast-kinetic analysis of recombinant human α and β myosin heavy chain motor domains. This represents the first such analysis of any human muscle myosin motor and the first of α-myosin from any species. Our findings reveal substantial isoform differences in individual kinetic parameters, overall contractile character, and predicted cycle times. For these parameters, α-subfragment 1 (S1) is far more similar to adult fast skeletal muscle myosin isoforms than to the slow β isoform despite 91% sequence identity between the motor domains of α- and β-myosin. Among the features that differentiate α- from β-S1: the ATP hydrolysis step of α-S1 is ~ten-fold faster than β-S1, α-S1 exhibits ~five-fold weaker actin affinity than β-S1, and actin·α-S1 exhibits rapid ADP release, which is >ten-fold faster than ADP release for β-S1. Overall, the cycle times are ten-fold faster for α-S1 but the portion of time each myosin spends tightly bound to actin (the duty ratio) is similar. Sequence analysis points to regions that might underlie the basis for this finding.

Item Type: Article
Uncontrolled keywords: Muscle Kinetics ATPase Contraction Heart
Subjects: Q Science
Divisions: Faculties > Sciences > School of Biosciences
Depositing User: Sue Davies
Date Deposited: 11 Feb 2013 09:57 UTC
Last Modified: 26 Apr 2013 09:24 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/33208 (The current URI for this page, for reference purposes)
  • Depositors only (login required):