A chemical and immunologic study of elastin and elastase Action of elastase on various substrates; The elastase-inhibitor of serum
Lab Invest 1. 5: 948-961
Elastin substrates prepared by extraction with NaOH, acetic and (HAc), and distilled water contained 1.21 1.43% hydroxyproline. HAc-elastin contained significantly more hexose than other substrates. Combined extraction with HAc and NaOH yielded the lowest substrate values for hexosamine. Elastolysates derived by the action of elastase on HAc-elastin yielded higher values for hexose and hexosamine than the other substrates. There was an increased amount of hexose and hexosamine in all elastolysates prepared at pH 7.5 as compared to pH 8.5. These and other quantitative data are discussed in relation to the chemical identity of elastin, with particular reference to the mucoprotein or sheath mucoid component of elastin. The comparative enzymic actions of elastin, papain, and chymotrypsin on elastin, casein, ovomucin, chalazae, and ovomucoid are presented. Elastase was active against only the first three. Elastase liberates more hexose from the insoluble substrates elastin and ovomucin than papain does, suggesting a comparatively greater affinity of elastase for the carbohydrate linkages of substrate. Chicken and human serum, containing elastase-inhibitor, significant inhibit elastolysis per se but have no measurable effect on casein-proteolysis by elastase. Elastase is highly antigenic. Solubilized elastin is probably non-antigenic.