Thermal Denaturation and Aggregation of Chicken Breast Muscle Myosin and Subfragments

Abstract

To elucidate the roles of the head and tail portions of chicken breast muscle myosin in gelation, the thermal stability and aggregation behavior of myosin and seven subfragments in 0.6 M NaCl, pH 6.5, were investigated, namely, myosin heavy chain (MHC), light chains (LC), heavy meromyosin (HMM), light meromyosin (LMM), rod, subfragment 2 (S-2), and subfragment 1 (S-1). Myosin had four independent cooperative endothermic transitions (T m) at 47, 54, 57, and 63 °C and aggregated from 50 to 70 °C. The MHC endotherm had peaks at 46, 54, and 64 °C and aggregated between 45 and 63 °C. S-1 unfolded in a single transition, having a T m of 47.7 °C, and aggregated from 49 to 53 °C. The rod melted between 30 and 63.3 °C and continuously aggregated over this temperature range. Initial unfolding of the rod occurred in the LMM region. S-2 was primarily responsible for denaturation and aggregation above 55 °C. Transition temperatures of 48 and 57 °C were recorded for LC; however, no aggregation occurred. The rod had the biggest influence on gel formation. Light meromyosin and S-1 contributed to gel structure at temperatures less than about 55 °C, whereas S-2 was responsible for matrix formation above 60 °C. Keywords: Myosin; gelation; differential scanning calorimetry; denaturation

Effects of different pre-salting methods on protein aggregation during heavy salting of cod fillets

“…For chicken myosin (0.6 M NaCl), the HMM-S2 transitions have been claimed to occur at higher temperatures (>55°C) than the LMM subunit. In the same study the transition temperatures of myosin light chains were reported to occur at 48 and 57°C (Smyth, Smith, Vega-Warner, & O'Neill, 1996).…”

“…The two stages of melting of proteins with an a-helical structure has been explained by a decrease in the inter-chain interaction and an unfolding of the helical structure. The helical structure is primarily destabilised by changes in electrostatic and hydrophobic interactions (Samejima, Ishioroshi, & Yasui, 1983;Smyth, Smith, Vega-Warner, & O'Neill, 1996).…”

Effects of high pressure and CaCl2 on properties of salt-soluble meat protein gels containing locust bean gum

“…Typical thermal transition temperatures for meat proteins range from 43 to 67°C for myosin and its subunits, 67 to 69°C for sarcoplasmic proteins, and 71 to 83°C for actin (Smyth, Smith, Vega-Warner, & O'Neill, 1996). SSMP is mainly composed of myosin, of which peak values of thermal transition temperature were 40.9-63.3°C (T peak1 ) for myosin head (heavy meromyosin) and 62.2-68.6°C (T peak2 ) for myosin tail (light meromyosin) (Amako & Xiong, 2001;Chen et al, 2007;Nagai et al, 1999).…”

The Influence of Heating and Cooling Process on the Water Binding in Transglutaminase-Modified Chicken Protein Preparation, Assessed Using Low-Field NMR

“…Wang and Smith (1994a) identified in the myosin isolated from the chicken breast muscle ten different protein domains. Smyth et al (1996) showed that the domain containing α-helix of light meromyosin was unfolded as a result of heating within the temperature range of 20-46°C. This suggests a thermal process of partial unfolding of myosin, as a result of which new, previously unavailable hydrophilic and hydrophobic groups were revealed.…”