Patent · US Expired

Subtilisin variants capable of cleaving substrates containing dibasic residues

US5780285A · kind A · utility

5Cited by
2References
1Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 3, 1995
Grant dateJul 14, 1998
Priority date
Expiry dateMar 3, 2015

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07K2319/75
  • WIPO fieldBiotechnology
  • WIPO sectorChemistry

Abstract

The bacterial serine protease, subtilisin BPN', has been mutated so that it will efficiently and selectively cleave substrates containing dibasic residues. A combination mutant, where Asn 62 was changed to Asp and Gly 166 was changed to Asp (N62D/G166D), had a larger than additive shift in specificity toward dibasic substrates. Suitable substrates of the variant subtilisin were revealed by sorting a library of phage particles (substrate phage) containing five contiguous randomized residues. This method identified a particularly good substrate, Asn-Leu-Met-Arg-Lys-, that was selectively cleaved in the context of a fusion protein by the N62D/G166D subtilisin variant. Accordingly, this variant subtilisin may be useful for cleaving fusion proteins with dibasic substrate linkers and processing hormones or other proteins (in vitro or in vivo) that contain dibasic cleavage sites.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.