Streptomyces proteases and improved streptomyces strains for expression of peptides and polypeptides
US5616485A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1993 |
| Grant date | Apr 1, 1997 |
| Priority date | — |
| Expiry date | Dec 23, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07K2319/02
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
A family of proteases endogenous to Streptomyces cells degrade heterologous proteins secreted from Streptomyces host cells. The previously unidentified proteases include (1) tripeptidyl aminopeptidase--Streptomyces ("Tap"), (2) a Streptomyces protease ("Ssp") which displayed significant amino acid sequence homology to Subtilisin BPN' and showed an ability to remove tripeprides from the amino termini of proteins and peptides, and (3) other proteases derived from Streptomyces which degraded certain substrates under certain conditions. Degradation was alleviated by selective inhibition of secreted proteases or by using hosts with impaired capabilities to produce proteases. An irreversible inhibitor was designed based upon the mechanism and substrate specificity of the target protease. Hosts secreting high amounts of proteases were selected. Impaired hosts were produced by deleting or altering the nucleotide sequence for the proteases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.