Patent ID: 7135307
Filing Date: 2006-11-14
Classification: A61K,C07K,C12N,C12Q,G01N

Abstract:
1. A membrane preparation from eukaryotic cells containing γ3 protease having an M r of approximately 60 kDa to 120 kDa during gel filtration analysis where the γ3 protease is catalytically active and has an activity that: is not susceptible to inhibition by L-685,458; is susceptible to inhibition by Pepstatin A; displays a pH optimum of 6.0; cleaves a substrate having an amino acid sequence comprising SEQ.ID.NO.:3 between positions 40 and 41 of SEQ.ID.NO.:3 or between positions 42 and 43 of SEQ.ID.NO.:3; where the membrane preparation has been prepared by a method comprising: (a) lysis of cells expressing γ3 protease to produce a lysate; (b) low speed centrifugation of the lysate to form a pellet and a supernatant from the lysate; (c) high speed centrifugation of the supernatant from step (b) to form a pellet and a supernatant from the supernatant from step (b); and (d) resuspension of the pellet from step (c) to form the membrane preparation; and (e) determining that the membrane preparation contains catalytically active γ3 protease by incubating the membrane preparation in the presence of a suitable substrate of γ3 protease under suitable conditions such that the γ3 protease cleaves at least a portion of the substrate into product and identifying product produced from the substrate by the γ3 protease.