ISSN:
1420-9071
Keywords:
Cross-bridge
;
dynamic laser light scattering
;
Limulus muscle
;
pyrophosphate
;
thick myofilament
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Pyrophosphate (PPi) is a non-hydrolyzable ATP analogue known to affect the binding between myosin heads and actin. By using a dynamic laser light scattering method, we have shown that 1–2 mM PPi enhances the increase in $$\bar \Gamma$$ values induced by Ca2+ in isolated thick myofilaments fromLimulus striated muscle. However, similar treatment has no effect on the $$\bar \Gamma$$ values of filaments suspended in either relaxing solution or ATP-free solution. $$\bar \Gamma$$ is the average linewidth of the photoelectron count autocorrelation function of the light scattered. PPi had no effect on the increase of $$\bar \Gamma$$ values by Sr2+ but it substantially increased the $$\bar \Gamma$$ values of the thick myofilaments suspended in Ba2+-substituted Ca2+ activating solution. The results show that PPi also affects the energy-requiring cyclic cross-bridge motions.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01956466
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