The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 07, 1993
Filed:
Sep. 12, 1989
Robert M Kelly, Ellicott City, MD (US);
Anne K Robinson, Philadelphia, PA (US);
Ilse I Blumentals, Silver Spring, MD (US);
Stephen H Brown, Owings Mills, MD (US);
Christian B Anfinsen, Baltimore, MD (US);
Johns Hopkins University, Baltimore, MD (US);
Abstract
Cell-free extracts from Pyrococcus furiosus were found to possess unusually high levels of proteolytic activity as measured by hydrolysis of azocasein; loss in activity was only 30% after incubation for 24 hours at 98.degree. C. and the half-life of proteolytic activity at that temperature was about 60 hours. Furthermore, cell-free extracts incubated at 98.degree. C. in 1% sodium dodecyl sulfate (SDS) for 24 hours yielded an SDS-resistant protease having a temperature optimum of at least 100.degree. C. The enzyme retained at least 40% of its activity when tested at 98.degree. C. by azocasein hydrolysis in the presence of 4M urea, 2M guanidinium chloride, 10 mM dithiothreitol or 150 mM .beta.-mercaptoethanol. The protease was found to have a pH optimum of 6.8 at 98.degree. C. and retained more than 45% of its activity at pH 9.3 and 82% of its activity at pH 4.5 in assays performed at those values. The protease was classified as a metalloprotease through inhibitor studies, and peptide hydrolysis showed trypsin-like cleavage with additional activities.