中文摘要：

用碱性蛋白酶水解食源性明胶以制备抗冻多肽,通过控制酶解条件获得具有抗冻活性的明胶多肽酶解液,并对其进行色谱分离、质谱鉴定及氨基酸全序列测定。结果表明：当酶与底物比1：15、酶解时间30min、酶解温度45℃时,所获得的明胶多肽酶解液的抗冻活性最高;酶解制备的明胶多肽液经过冷-热循环（cold-heat-stage）后抑制冰晶生长和抗冻活性表现出特定的规律,说明酶解条件的控制优化是实现明胶多肽液抗冻活性的关键。通过Sephadex G-50、SP Sephadex C-25、C18-RPLC色谱分离和MALDI-TOF质谱鉴定,确定分子质量为2107D的特异性多肽表现出显著的抗冻活性。通过Edman降解法测得其氨基酸全序列为GERGFPGERGSPGAQGLQGPR。

英文摘要：

Food-origin gelatin peptides with antifreeze activity were obtained under controlled hydrolysis conditions by alcalase.The specific antifreeze peptide was isolated by chromatography and identified by mass spectroscopy.The full amino acid sequence was also determined.The results showed that gelatin peptides prepared at [E]/[S] ratio of 1：15,hydrolysis time of 30 min and hydrolysis temperature of 45 ℃ revealed the best antifreeze activity.The antifreeze peptide on ice crystal inhibition showed specific rules during cold-heat-stage cycles.The control of hydrolysis conditions is critical.The specific antifreeze peptide was fractionated by size exclusion（Sephadex G-50）,ion exchange（sulfopropyl Sephadex C-25） column and C18-HPLC,respectively.The molecular mass of the specific antifreeze peptide was determined to be 2107 D by matrixassisted laser desorption ionization-time-of-flight（MALDI-TOF） mass spectrometry.The purified gelatin peptide with molecular mass of 2107 D strongly inhibited the growth of ice crystal in ice cream mix.The full amino acid sequence was determined to be GERGFPGERGSPGAQGLQGPR by Edman degradation.