Some properties of the products of reaction of tadpole collagenase with collagen.
Some properties of the products of reaction of tadpole collagenase with collagen.
复制标题
蝌蚪胶原酶与胶原蛋白反应产物的一些性质。
DOI：
10.1021/bi00854a021
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发表时间：
1967
期刊：
影响因子：
2.9
通讯作者：
J. Gross
中科院分区：
文献类型：
--
作者：
T. Sakai;J. Gross
摘要：利用硫酸铵分级法分离蝌蚪胶原酶作用于哺乳动物和蝌蚪胶原的裂解产物，并对其氨基酸组成、大小、形状、分子量、构象和稳定性进行了分析。用沉降平衡超离心法测定的分子量与早期的观察结果非常一致，即酶作用产生的两个片段占胶原分子的四分之三和四分之一。小片段（TCB）、较大片段（TCA）和完整分子（TC）的数均分子量值分别为70，000、202，000和298，000。从粘度测量的分子长度和刚度的计算是一致的刚性棒结构的两个片段，一个，四分之一，和其他的，三，四分之一的完整分子。旋光色散测量表明，在碎片中保留了螺旋内容。的片段热变性更容易比胶原蛋白;在酸性pH值的Tm值分别为32和29 TCA和TCB，TC（小牛皮肤）相比，36。蝌蚪胶原蛋白在酸性pH下对TCB、TCA和TC的Tm值分别为23.2、24.5和29;在中性pH下，该值高1-2。TCB和TCA在15种氨基酸的含量上彼此存在显著差异;只有甘氨酸、谷氨酸和天冬氨酸的差异小于10%。TCB的总亚氨基酸含量高于TCA和TC，但变性温度较低。与天然胶原相比，片段的其他特征点是在中性pH下溶解度增加，对胰蛋白酶降解的敏感性更大。根据这些发现提出了胶原生理性再吸收机制的假说。
Takahiro Sakaif andJerome Gross abstract: Cleavage products of the action of tadpole collagenase on mammalian and tadpole collagens have been isolated and separated by ammonium sulfate fractionation, andhave been analyzed for amino acid composition, size, shape, molecular weight, conformation, and stability. Molecular weight determinations by sedimentation equilibrium ultracentrifugation agree closely with the earlier observations that thetwo frag-ments produced by enzyme action represent threequarters and one-quarter of the collagen molecule. Values for the number-average molecular weight for the small fragment (TCB), the larger fragment (TCA), and the intact molecule (TC) were 70,000, 202,000, and 298,000, respectively. Calculations for molecular length and rigidity from viscosity measure-ments were consistent with a rigid rod structure for two fragments, one, one-quarter, and the other, three-, quarters of the intact molecule. Optical rotatory dispersion measurements indicated that helical content was preserved in thefragments. The fragments heat denatured more readily than collagen; at acid pH Tm values were 32 and 29 for TCA and TCB, respectively, as compared with 36 for TC (calf skin). Tadpole collagen at acid pH gave Tm values of 23.2, 24.5, and 29, respectively, for TCB, TCA, and TC; at neutralpH the values were 1-2 higher. TCBand TCA differed significantly from each other in the content of 15 of the amino acids; only glycine, glutamic acid, and aspartic acid showed less than 10% difference. The total imino acid percentage was higher in TCB than in either TCA or TC, yet the denaturation temperature was lower. Other points characteristic of the fragments as compared to native collagen were increased solubility at neutral pH and greater susceptibility to degradation by trypsin. A hypothesis on the mechanism of physiologic resorption of collagen based on these findings is proposed.