title: Decomposition of insoluble and hard-to-degrade animal proteins by enzyme E77 and its potential applications.
abstract: Insoluble and hard-to-degrade animal proteins are group of troublesome proteins, such as collagen, elastin, keratin, and prion proteins that are largely generated by the meat industry and ultimately converted to industrial wastes. We analyzed the ability of the abnormal prion protein-degrading enzyme E77 to degrade insoluble and hard-to-degrade animal proteins including keratin, collagen, and elastin. The results indicate that E77 has a much higher keratinolytic activity than proteinase K and subtilisin. Maximal E77 keratinolytic activity was observed at pH 12.0 and 65 °C. E77 was also adsorbed by keratin in a pH-independent manner. E77 showed lower collagenolytic and elastinolytic specificities than proteinase K and subtilisin. Moreover, E77 treatment did not damage collagens in ovine small intestines but did almost completely remove the muscles. We consider that E77 has the potential ability for application in the processing of animal feedstuffs and sausages.
authors.affiliation: Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, 650091, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Shinji
authors.initials: S
authors.lastname: Mitsuiki
authors.forename: Mikako
authors.initials: M
authors.lastname: Takasugi
authors.forename: Masashi
authors.initials: M
authors.lastname: Sakai
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Goto
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kanouchi
authors.forename: Tatsuzo
authors.initials: T
authors.lastname: Oka
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D004549:Elastin / Q000378:metabolism*; D019286:Endopeptidase K / Q000378:metabolism; D005524:Food Technology / Q000379:methods; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007421:Intestine, Small / Q000737:chemistry / Q000378:metabolism; D007633:Keratins / Q000378:metabolism*; D007700:Kinetics; D008461:Meat Products; D009132:Muscles / Q000737:chemistry / Q000378:metabolism; D011328:Prions / Q000378:metabolism*; D034561:Sheep, Domestic; D013302:Streptomyces / Q000201:enzymology*; D013381:Subtilisins / Q000378:metabolism; D014866:Waste Products
chemical_list: D001426:Bacterial Proteins; D011328:Prions; D014866:Waste Products; D007633:Keratins; D003094:Collagen; D004549:Elastin; D013381:Subtilisins; D019286:Endopeptidase K