摘要
本研究分别运用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（sodium dodecyl sulfate-polyacrylamide gelelectropHoresis,SDS-PAGe）、紫外光谱、氨基酸分析、质谱和分子信息技术,比较中国山猪心肌高铁肌红蛋白（pig metmyoglobin,pMetMb）分子信息和三维结构。结果表明：pMetMb肽链至少含有133种氨基酸组分,但较hMb缺少脯氨酸（Pro）和精氨酸（Arg）;与美国国家生物技术信息中心（national Center for Biotechnology Information,nCBI）数据库猪野生型gi｜494385比对,其匹配度79.7%（置信度100%）,故推测肽链长度在133~153之间。pMetMb含有7个α螺旋和2个310螺旋,由于310螺旋存在（马Mb没有）,使肽链中疏水基团作用加强,形成更加紧密盘叠的球状亚基;第6和7螺旋的His64和His93的咪唑基团N（Im n—）与Fe2＋/Fe3＋键合,构成核心heme-Fe功能域;它镶嵌于蛋白质内部疏水结构内,更便于电子传递和Fe2＋/Fe 3＋氧化还原反应,维系肉色。
The structural elucidation of metmyoglobin（Mb） is helpful for understanding the mechanism of meat color. Molecular information and three-dimensional structure of metmyoglobin（pMetMb） in pig myocardium were studied by SDS-PAGE, UV spectroscopy, amino acid analysis, mass spectrometry and bioinformatics. The peptide chain of p Met Mb was composed of at least 133 amino acids（AAs）. AAs from pMetMb lacked proline（Pro） and arginine（Arg） compared with horse Mb（hMb）. pMetMb was matched 79.7%（100% confidence） with gi｜494385 in NCBI database, suggesting that the length of pMetMb peptide was in the range of 133–153 AAs including 7 α-helixes and 2 310 helixes in its secondary structure. Due to the 310 helixes, hydrophobic groups in p Met Mb had increased interaction with each other and the peptide chain highly folded as globin subunit, while hMb contained no 310 helixes. Both His64 and His93 located at the 6th α-helix and 7th α-helix contained imidazole group with nitrogen（N-） that could bind with Fe2＋/Fe3＋ to form heme-Fe domain which was embed into hydrophobic groups, facilitating electron transfer and oxidation-reduction and consequently for maintaining desirable meat color.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2015年第21期62-67,共6页
Food Science
基金
江苏省自然科学基金项目(BK2009402)
江苏省农业科技创新项目(CX(11)1301)
关键词
高铁肌红蛋白
氨基酸种类
Α螺旋
分子结构信息
猪心肌
metmyoglobin（MetMb）
amino acids
alpha helix
molecular and structural information
pig myocardium
