Premium
Viscoelastic and light scattering studies on thermally induced sol to gel phase transition in fish myosin solutions
Author(s) -
Kouchi Sawa,
Kondo Shingo,
Ooi Kazuko,
Ichikawa Hisashi,
Dobashi Toshiaki
Publication year - 2003
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10388
Subject(s) - chemistry , viscoelasticity , myosin , hydrodynamic radius , analytical chemistry (journal) , dynamic light scattering , viscosity , phase transition , phase (matter) , chromatography , thermodynamics , micelle , materials science , composite material , nanotechnology , biochemistry , organic chemistry , physics , aqueous solution , nanoparticle
Viscoelastic (VE) and dynamic light scattering (DLS) analyses of fish (white croaker) myosin solutions were performed at myosin concentrations of 30mg/mL for VE and 0.1 mg/mL for DLS at 0.6 M KCl and pH 7.0 to clarify thermally induced gelation. The hydrodynamic radius R h considerably decreased around 30–35°C. The shear modulus G was constant below 25°C and increased by incubating the sample at 30°C. G further increased as the temperature of the incubated sample decreased. The curves of G vs T for different time courses showed a sharp peak around 35°C and a moderate peak around 60°C in the heating process, while a stepwise increase in G was observed around 30°C in the cooling process when the temperature was elevated to not more than 60°C. No distinct stepwise change was observed once the temperature of the sample exceeded 60°C. The absolute value of G strongly depended on the maximum elevated temperature and the incubation time at that temperature. The corresponding behavior of the viscosity η was observed for each time course. Based on these results, the mechanism of thermally induced gelation of myosin solutions is discussed in view of SS bridge formation in the head and tail portions and unwinding/rewinding of coiled‐coil α‐helices in the tail portion. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 498–507, 2003