title: Physicochemical properties of natural actomyosin from threadfin bream (Nemipterus spp.) induced by high hydrostatic pressure.
abstract: Changes of physicochemical properties in natural actomyosin (NAM) from threadfin bream (Nemipterus spp.) induced by high hydrostatic pressure (200, 400, 600MPa for 10, 30, 50min) were studied. The increase in turbidity of NAM was coincidental with the decrease in protein solubility with increasing pressure and time, suggesting the formation of protein aggregates. SDS-PAGE showed that polymerisation and degradation of myosin heavy chain were induced by high pressure. Ca(2+)-ATPase activity of NAM treated by high pressure was lost, suggesting the denaturation of myosin and the dissociation of actomyosin complex. Surface hydrophobicity of NAM increased when the pressure and pressurization time increased, indicating that the exposed hydrophobic residues increased upon application of high pressure. Decrease in total sulfhydryl content and increase in surface-reactive sulfhydryl content of NAM samples were observed with the extension of pressurizing time, indicating the formation of disulphide bonds through oxidation of SH groups or disulphide interchanges. The above changes of physicochemical properties suggested conformational changes of NAM from muscle of threadfin bream induced by high hydrostatic pressure.
authors.affiliation: Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China. Electronic address: zhouam@scau.edu.cn.
authors.forename: Aimei
authors.initials: A
authors.lastname: Zhou
authors.affiliation: Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
authors.forename: Liying
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liang
authors.affiliation: Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand.
authors.forename: Soottawat
authors.initials: S
authors.lastname: Benjakul
authors.affiliation: Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Shi
authors.affiliation: Department of Food Science, College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510642, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
mesh_terms: D000205:Actomyosin / Q000737:chemistry*; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000737:chemistry; D004220:Disulfides / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005396:Fish Products; D005399:Fishes; D057927:Hydrophobic and Hydrophilic Interactions; D006874:Hydrostatic Pressure; D008968:Molecular Conformation; D009218:Myosins / Q000737:chemistry; D009391:Nephelometry and Turbidimetry; D010473:Perciformes; D011312:Pressure; D017747:Seafood / Q000032:analysis; D012995:Solubility; D013499:Surface Properties; D013997:Time Factors
chemical_list: D004220:Disulfides; D000205:Actomyosin; D009218:Myosins; D000252:Calcium-Transporting ATPases
keywords: High hydrostatic pressure; Natural actomyosin; Physicochemical properties; Threadfin bream