Analysis of the cloned protease III gene (ptr) from Escherichia coli K-12 has demonstrated that in addition to the previously characterized 110,000-Mr protease III protein, a second 50,000-Mr polypeptide (p50) is derived from the amino-terminal end of the coding sequence. The p50 polypeptide is found predominantly in the periplasmic space along with protease III, but does not proteolytically de...

Proteases play important roles in a variety of disease processes. Understanding their biological functions underpins the efforts of drug discovery. We have developed a bioluminescent protease assay using a circularly permuted form of firefly luciferase, wherein the native enzyme termini were joined by a peptide containing a protease site of interest. Protease cleavage of these mutant luciferase...

We have developed a high throughput assay for the measurement of protease activity in solution. This technology will accelerate research in functional proteomics and enable biologists to streamline protease substrate evaluation and optimization. The peptide sequences that serve as protease substrates in this assay are labeled on the carboxy terminus with a biotin moiety and a fluorescent tag is...

In this study we observed the proliferation of Pseudomonas fluorescens (P. fluorescens) in mouse organ homogenates at 4 degrees C. P. fluorescens secreted a protease possessing properties different from those of the mammalian tissue proteases. The specificity of this protease required a basic amino acid residue at the P1 position at a pH optimum of 6.0. The specificity of the protease was simil...

CARMA-BCL10-MALT1 signalosomes play important roles in antigen receptor signaling and other pathways. Previous studies have suggested that as part of this complex, MALT1 functions as both a scaffolding protein to activate NF-κB through recruitment of ubiquitin ligases, and as a protease to cleave and inactivate downstream inhibitory signaling proteins. However, our understanding of the relative...

Although many human immunodeficiency virus type 1 (HIV-1)-infected persons are treated with multiple protease inhibitors in combination or in succession, mutation patterns of protease isolates from these persons have not been characterized. We collected and analyzed 2,244 subtype B HIV-1 isolates from 1,919 persons with different protease inhibitor experiences: 1,004 isolates from untreated per...

Proteolytic enzymes are key signaling molecules in both normal physiological processes and various diseases. After synthesis, protease activity is tightly controlled. Consequently, levels of protease messenger RNA and protein often are not good indicators of total protease activity. To more accurately assign function to new proteases, investigators require methods that can be used to detect and...

Protease A and protease B are extracellular proteins which are secreted by Streptomyces griseus. The genes encoding protease A (sprA) and protease B (sprB) were isolated from an S. griseus genomic library by using a synthetic oligonucleotide probe. Fragments containing sprA and sprB were characterized by hybridization and demonstration of proteolytic activity in Streptomyces lividans. Each DNA ...

The laboratory evolution of protease enzymes has the potential to generate proteases with therapeutically relevant specificities and to assess the vulnerability of protease inhibitor drug candidates to the evolution of drug resistance. Here we describe a system for the continuous directed evolution of proteases using phage-assisted continuous evolution (PACE) that links the proteolysis of a tar...

Two 2 × 2 factorial experiments were conducted to investigate the interaction between xylanase (0 vs. 200 mg/kg) and protease (0 vs. 200 mg/kg) enzyme supplementation on growth performance (Exp. 1) and coefficient of ileal and total tract apparent digestibility in grower-finisher pigs (Exp. 2). One hundred and twenty-eight individual fed pigs (BW = 34.2 kg; n = 32) were assigned to 1 of 4 dieta...