Elastolysis of kappa-elastin sub-fractions by pancreatic and leukocyte elastases.
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.
Boudjelthia
A K
AK
Biochimie Analytique, URA CNRS 244, I.C.B.M.C., Université Lyon I, Villeurbanne, France.
Saulnier
J
J
Wallach
J M
JM
D000818:Animals; D003217:Conductometry; D004549:Elastin / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D007962:Leukocytes / Q000201:enzymology*; D008970:Molecular Weight; D010179:Pancreas / Q000201:enzymology*; D010446:Peptide Fragments / Q000302:isolation & purification / Q000378:metabolism*; D013552:Swine
D010446:Peptide Fragments; D004549:Elastin