Purification and Characterization of a Keratinase from a Feather-Degrading Bacillus licheniformis Strain

A keratinase was isolated from the culture medium of feather-degrading Bacillus licheniformis PWD-1 by use of an assay of the hydrolysis of azokeratin. Membrane ultrafiltration and carboxymethyl cellulose ion-exchange and Sephadex G-75 gel chromatographies were used to purify the enzyme. The specific activity of the purified keratinase relative to that in the original medium was approximately 70-fold. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis and Sephadex G-75 chromatography indicated that the purified keratinase is monomeric and has a molecular mass of 33 kDa. The optimum pH and the pI were determined to be 7.5 and 7.25, respectively. Under standard assay conditions, the apparent temperature optimum was 50 degrees C. The enzyme is stable when stored at -20 degrees C. The purified keratinase hydrolyzes a broad range of substrates and displays higher proteolytic activity than most proteases. In practical applications, keratinase is a useful enzyme for promoting the hydrolysis of feather keratin and improving the digestibility of feather meal.

Anti-IgG immobilized controlled-pore glass. Thionyl chloride-activated succinamidopropyl-glass as a covalent immobilization matrix

Rabbit anti-bovine IgG was covalently immobilized on thionyl chloride-activated succinamidopropyl controlled-pore glass (CPG) beads (3000 A pore diam; 120/200 mesh). Thionyl chloride-activated beads remained stable for over 1 y retaining full capability of immobilizing protein upon recirculation of protein solution. The immobilized anti-bovine IgG is capable of binding IgG with a dissociation constant (Kd) of 9.45 x 10(-7) M and a capacity of 0.85 g/L of matrix. A column of immobilized anti-IgG is able to remove all detectable contaminating IgG from partially purified enzyme preparations of sulfhydryl oxidase and gamma-glutamyltransferase as determined by ELISA and Western blot. The column matrix could be regenerated by washing with 0.1M acetic acid, pH 2.8.

Immunocytochemical and scanning electron microscopic studies of atherosclerosis in Japanese quail

The major cellular components of atherosclerotic lesions in several species have been shown to be smooth muscle cells (SMC) and macrophages. Many studies suggest the composition of a lesion varies depending on the stage of lesion development. For example, macrophages are believed to be involved in the initial events of fatty streak formation in many animals. This communication presents the first cellular study of quail atherosclerosis and demonstrates the alteration of cellular structure during the process of the disease in quail fed a cholesterol diet. Monoclonal antibodies to alpha-actin and chicken macrophages effectively identified the presence of SMC and macrophages, respectively, as constituents of the atherosclerotic lesions. Macrophage presence, as well as SMC proliferation, was observed in early lesions. Although the first cell type to be involved in the initial stages of atherogenesis cannot be defined, the results suggest early intervention of macrophages and SMC. Scanning electron microscopic examination of the aortic arch demonstrates the obvious differences in appearance of the endothelial surface of normal and diseased quail. The accumulation of subendothelial foam cells causes the lumen surface to bulge irregularly into the lumen. The results of the present study are important to the evaluation of the key cellular events of atherogenesis.