鲍鱼肌肉胶原蛋白的提取与性质研究

Extraction and Characterization of Collagens from Abalone Muscle

摘要:

提取了鲍鱼肌肉酸溶性胶原蛋白(ASC)和不同胃蛋白酶质量浓度下的酶溶性胶原蛋白(PSC)，并对它们的理化性质进行研究和比较。结果发现，ASC的提取率只有0.63%，低于任一PSC。氨基酸组成结果显示，ASC和PSC的Gly含量都没有达到氨基酸总量的1/3，但都含有12.03~16.30个Cys残基和9.75~14.68个Tyr残基。根据SDS-PAGE图谱，发现鲍鱼肌肉ASC的α亚基是由160 ku的α1、140 ku的α2和130 ku的α3肽链组成，而PSC则是由3条α1肽链组成。ASC的最大紫外吸收峰出现在224 nm，而PSC却偏移至228 nm。ASC与PSC在粘度特性上存在明显的差异，结果表现为ASC的热变性温度高于任一PSC。Zeta电位测定结果表明，无论是ASC还是PSC，其等电点均在pH 4.90附近。pH和NaCl对ASC的溶解性影响趋势与PSC基本一致，但在同一pH或NaCl浓度下，PSC的溶解度高于ASC，且随着胃蛋白酶添加量的增加出现一定程度的上升。综上所述，鲍鱼肌肉ASC与PSC在理化性质上具有明显的区别。

Abstract:

Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were extracted from abalone (Haliotis discus hannai) muscle, and their physicochemical properties were investigated and compared. The results showed that the extraction yield of ASC from abalone muscle was 0.63%, which was lower than that of any PSC extracted at different pepsin concentrations. Amino acid composition analysis showed that the Gly content of both ASC and PSC were less than one-third of the total amino acids; however, both ASC and PSC contained 12.03~16.30 Cys residues and 9.75~14.68 Tyr residues per 1000 residues. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicated that the α subunits of ASC were composed of α1 (160 ku), α2 (140 ku), and α3 (130 ku), but there were only three α1 peptide chains found in PSC. The maximum ultraviolet absorption of ASC was observed at 224 nm, while that of PSC shifted to 228 nm. Significant differences were observed between the viscosity of ASC and PSC; thus, the denaturation temperature of ASC was higher than that of any PSC. Based on the results of zeta potential measurement, both PSC and ASC had a similar isoelectric point at approximately pH 4.90. The effects of pH and NaCl concentration on the solubility of ASC were similar to those of PSC. However, at the same pH or NaCl concentration, the solubility of PSC was higher than that of ASC, and it was further increased to a certain extent with increasing pepsin concentration. In conclusion, these results suggest that the physicochemical properties of ASC and PSC from abalone muscle differ significantly.