膠原蛋白是構成身體結締組織的主要成分，由於其特殊的三股螺旋結構，以及單體與單體間聚合形成生物高分子的特性，使其在醫藥生技、組織工程、化妝品以及食品添加等生物科技上的用途，快速而蓬勃地發展。
本研究以牛膠原蛋白第一型（bovine collagen type I）為材料，利用胃蛋白酵素（pepsin）在弱酸中進行水解，以製造分子量不同之膠原蛋白片段。研究結果顯示在4℃下，胃蛋白酵素水解反應之主要產物以MALDI-TOF MS測量產物為93 kDa之片段，反之在高溫下（40℃），胃蛋白酵素會將膠原膠原蛋白切成許多分子量較小之片段。
經胃蛋白酵素處理之膠原蛋白不但在水溶液中之溶解度增加，而且對骨細胞增生之活性亦增加兩倍。

Collagen is the most abundance biopolymer in connective tissue. Its special triple helical structure and biopolymer property has made it widely used in biopharmaceutical, tissue engineering, cosmetics and food industries.

In this research, we used pepsin to cleave bovine type I collagen and studied pepsin-cleaved collagen fragments. Under low temperature condition (4℃), pepsin only cleaved off only a small fragment from collagen and yield a 93 kDa collagen fragment as determined by MALDI mass spectrometry. Under higher temperature condition (40℃), the collagen was cleaved into many small fragment.

The cleavage of collagen by pepsin not only improves its water solubility but also improves its biological activity. The result of mouse osteoblast cell proliferation assay showed that pepsin-cleavage collagen is approximately two fold better than the uncleavaed collagen.

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