Boudjelthia A K, Saulnier J, Wallach J M
Biochimie Analytique, URA CNRS 244, I.C.B.M.C., Université Lyon I, Villeurbanne, France.
Biochem Int. 1990;21(1):145-53.
Kappa-elastin peptides, obtained from insoluble elastin by organo-alkaline hydrolysis, were fractioned by gel filtration on Biogel agarose. Rates of hydrolysis by pancreatic and leukocyte elastases of the fractions were measured using a conductometric method. Kinetics obey to Michaelis-Menten model for both substrates and enzymes. KM and Vmax values derived from Lineweaver-Burk plots indicate that, if KM remains quite constant, differences were observed in catalytic rates. The kcat values decreased with molecular-weight, the high-molecular-weight kappa-elastin peptides being hydrolyzed 3 to 5 times faster than the low-molecular-weight ones. Apparent differences between potentiometric (pH-Stat) and conductometric results were discussed, in relation with buffer capacity of soluble and insoluble elastins.
通过有机碱水解从不溶性弹性蛋白中获得的κ-弹性蛋白肽，在Biogel琼脂糖上进行凝胶过滤分级。使用电导法测量各组分被胰弹性蛋白酶和白细胞弹性蛋白酶水解的速率。底物和酶的动力学均符合米氏模型。从Lineweaver-Burk图得出的KM和Vmax值表明，如果KM保持相当恒定，则在催化速率上会观察到差异。kcat值随分子量降低，高分子量的κ-弹性蛋白肽比低分子量的肽水解速度快3至5倍。讨论了电位滴定法（pH计）和电导法结果之间的明显差异，以及可溶性和不溶性弹性蛋白的缓冲能力。
