Streptomyces proteases and methods for improved secretion of recombinantly-expressed proteins
US5856166A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1994 |
| Grant date | Jan 5, 1999 |
| Priority date | — |
| Expiry date | Jun 24, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07K2319/02
- WIPO fieldBiotechnology
- WIPO sectorChemistry
Abstract
A family of proteases endogenous to Streptomyces cells degrades 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 tripeptides 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.