以膠體電泳分析轉穀醯胺酶對羊乳蛋白之聚合作用

Gel Electrophoresis Analysis of Transglutaminase-induced Polymerization of Goat Milk Proteins

陳俊吉(Chun-Chi Chen) ； 陳伶婕(Ling-Chieh Chen) ； 謝榮峯(Jung-Feng Hsieh)

《輔仁民生學誌》 19卷2期 (2013/12) Pp. 39-51

摘要

本研究是以膠體電泳分析轉穀醯胺酶（transglutaminase）對羊乳蛋白之聚合，當羊乳中添加轉穀醯胺酶（2.0 units/mL）並於50°C下作用2小時後，電泳膠片上α_s-酪蛋白（α_s-casein）之影像強度由385.3減少至249.8，β-酪蛋白（β-casein）的強度由5361.1減少至1508.5，κ-酪蛋白（κ-casein）的強度由1245.8減少至77.6，而β-乳球蛋白（β-lactoglobulin）的強度由1129.4減少至349.4，顯示轉穀醯胺酶促使羊乳中α_s-酪蛋白（35.1%）、β-酪蛋白（71.8%）、κ-酪蛋白（93.7%）和β-乳球蛋白（69.0%）產生聚合作用。而當羊乳添加轉穀醯胺酶（2.0units/mL）並於50°C下分別作用0、1、2及3小時，羊乳蛋白隨作用時間增加而顯著產生聚合反應，高分子量之聚合物也隨作用時間而變多，當作用3小時後，電泳膠片上α_s-酪蛋白的影像強度由592.7減少至186.1，β-酪蛋白的強度由4915.4減少至1710.8，κ-酪蛋白的強度由1384.3減少至66.7，且β-乳球蛋白的強度由1002.2減少至480.5。由本研究的分析得知，羊乳中α_s-酪蛋白、β-酪蛋白、κ-酪蛋白和β-乳球蛋白受轉穀醯胺酶催化形成分子間（內）的架橋反應，並形成高分子量之聚合物。本研究已分析轉穀醯胺酶與羊乳蛋白之作用機制，未來可作為轉穀醯胺酶應用於羊乳製品的學理基礎。

關鍵字

羊乳蛋白 ； 轉穀醯胺酶 ； 膠體電泳 ； 酪蛋白

並列摘要

This study analyzed the transglutaminase-induced polymerization of goat milk proteins using gel electrophoresis. Transglutaminase (2.0 units/mL) was added to goat milk at 50°C, and the solution was incubated for 2 h. The total intensity of α_s-casein, β-casein, κ-casein and β-lactoglobulin protein bands decreased in goat milk from 385.3,5361.1,1245.8 and 1129.4 to 249.8,1508.5,77.6 and 349.4 on the gel electrophoresis, respectively. Specifically, 35.1%of α_s-casein, 71.8% of β-casein, 93.7% of κ-casein, and 69.0% of β-lactoglobulin were polymerized. Goat milk with added transglutaminase (2.0units/mL) was also incubated at 50°C for 0,1,2, and 3 h. Our analysis of that experiment clearly indicates that goat milk caseins were polymerized, and that the protein content increased over time. Following a 3 h incubation period, gel electrophoresis revealed a drop in the total intensity of α_s-casein (from 592.7 to 186.1), β-casein (from 4915.4 to 1710.8), κ-casein (from 1384.3 to 66.7), and β-lactoglobulin (from 1002.2 to 480.5). These results demonstrate that adding transglutaminase to the goat milk caused the protein content to increase through inter- and/or intra-molecular crosslinking. Therefore, in this study, transglutaminase with goat milk proteins mechanism has clearly analyzed that utilized in dairy industry to provide important theoretical foundation.

並列關鍵字

Goat milk protein ； Transglutaminase ； Gel electrophoresis ； Casein