Abstract
A trypsin-type protease was purified to enzymatic homogeneity from human umbilical vein endothelial cells by sequential affinity chromatographies. The enzyme specifically hydrolyzed dibasic substrates with leucine at the P3 positions, but scarcely hydrolyzed the other substrates tested. The enzyme was strongly inhibited by the Kunitz inhibitor domain peptide of Alzheimer's disease amyloid protein precursor (Ki value, 0.35 nM) and by the microbial inhibitors leupeptin and anti-pain. These results, together with a previous finding of a significant increase in the expression of Alzheimer's amyloid protein precursors (beta APPs) with the Kunitz inhibitor domain in Alzheimer's disease, suggest that the activity of the trypsin-type protease is suppressed by an increase of beta APPs with inhibitor activity in Alzheimer's disease, resulting in aberrant intracellular protein catabolism including degradation of beta APPs and beta-protein deposition.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
