Journal: BMC Biotechnology

Article Title: On the activity loss of hydrolases in organic solvents: II. a mechanistic study of subtilisin Carlsberg

doi: 10.1186/1472-6750-6-51

Figure Lengend Snippet: Effect of water (0.5 % v/v) and controlled water activity during incubation of 4-EFPO-TEMPO-labeled Subtilisin Carlsberg in 1,4-dioxane by EPR Spectroscopy.

Article Snippet: We have previously reported that the activity of the serine protease subtilisin Carlsberg is significantly reduced upon storage in several organic solvents, irrespective of its preparation, hydration, hydrophobicity of the solvent, the reaction temperature and of the substrates used [ ].

Techniques: Activity Assay, Incubation, Labeling, Electron Paramagnetic Resonance, Spectroscopy

Journal: BMC Biotechnology

Article Title: On the activity loss of hydrolases in organic solvents: II. a mechanistic study of subtilisin Carlsberg

doi: 10.1186/1472-6750-6-51

Figure Lengend Snippet: Storage stability of lyophilized subtilisin Carlsberg in 1,4-dioxane: (○) neat, (●) with 0.5% H 2 O added, and (▲) controlling water activity with BaBr 2 salts.

Article Snippet: We have previously reported that the activity of the serine protease subtilisin Carlsberg is significantly reduced upon storage in several organic solvents, irrespective of its preparation, hydration, hydrophobicity of the solvent, the reaction temperature and of the substrates used [ ].

Techniques: Activity Assay

Journal: BMC Biotechnology

Article Title: On the activity loss of hydrolases in organic solvents: II. a mechanistic study of subtilisin Carlsberg

doi: 10.1186/1472-6750-6-51

Figure Lengend Snippet: Storage stability of subtilisin Carlsberg co-lyophilized with methyl-β-cyclodextrin in 1,4-dioxane: (○) neat, (●) with 0.5% H 2 O added, and (▲) controlling water activity with BaBr 2 salts.

Article Snippet: We have previously reported that the activity of the serine protease subtilisin Carlsberg is significantly reduced upon storage in several organic solvents, irrespective of its preparation, hydration, hydrophobicity of the solvent, the reaction temperature and of the substrates used [ ].

Techniques: Activity Assay

Journal: mBio

Article Title: A Novel Neuraminidase-Dependent Hemagglutinin Cleavage Mechanism Enables the Systemic Spread of an H7N6 Avian Influenza Virus

doi: 10.1128/mBio.02369-19

Figure Lengend Snippet: Viral growth kinetics of A/Mdk/6L/07 and recombinant viruses with or without host protease inhibitor and trypsin in vitro . The inhibitory effect of protease inhibitors (aprotinin, leupeptin, and argatroban) on the replication of A/Mdk/6L/07 (H7N6) (A) and a modified virus, 6L PKG338_QS (B), containing modified HA cleavage sites in MDCK cells. MDCK cells were infected with A/Mdk/6L/07 (H7N6) and 6L PKG338_QS at an MOI of 0.0001, and samples were collected at 12, 24, 48, and 72 hpi. 6L, A/Mdk/6L/07 (H7N6); 6L PKG338_QS, 6L PKG338_QS virus modified at the indicated position of the specified amino acids by using the A/Mdk/6L/07 (H7N6) virus as a backbone; +, treated; −, untreated. *, P

Article Snippet: The serine protease inhibitors aprotinin (Sigma-Aldrich) and leupeptin (Sigma-Aldrich) were used at a concentration of 50 μg/ml (approximate 100 μM) in similar assays.

Techniques: Recombinant, Protease Inhibitor, In Vitro, Modification, Infection

Journal: PLoS Neglected Tropical Diseases

Article Title: SmSP2: A serine protease secreted by the blood fluke pathogen Schistosoma mansoni with anti-hemostatic properties

doi: 10.1371/journal.pntd.0006446

Figure Lengend Snippet: Substrate specificity and pH profile of SmSP2. (A) Activity of rSmSP2 was probed using a panel of peptidyl fluorogenic substrates used to assay trypsin-like and chymotrypsin/elastase-like serine proteases. Substrate hydrolysis was measured in a kinetic assay at pH 8.0. The mean values ± S.D. of three replicates are normalized to the maximum value. Amino acid residues at P1 and P2 positions are highlighted by the grey bar. (B) The pH profiles of rSmSP2 and native SmSP2 activity in extracts of adult worms. Activity was measured in a kinetic assay using the fluorogenic substrate P-F-R-AMC. The native activity (sensitive to the serine protease inhibitor Pefabloc SC) was measured in the presence of 10 μM E-64 and 1 mM EDTA to prevent undesired proteolysis of the substrate by cysteine proteases and metalloproteases, respectively. The mean values of three replicates, expressed as a percentage normalized to the highest value, are shown (standard deviation values are within 5% of the mean). (C) The pH stability of rSmSP2. Activity of rSmSP2 was measured at pH 8.0 in a kinetic assay as in (B) after incubation of the enzyme at pH 3 to 11 for different times. The mean values of three replicates, expressed as a percentage normalized to activity of non-incubated rSmSP2, are shown.

Article Snippet: The competitive labeling reaction was also performed after treatment of SmSP2 for 15 min at 37°C with 1 mM serine protease inhibitor Pefabloc SC (Sigma-Aldrich).

Techniques: Activity Assay, Kinetic Assay, Protease Inhibitor, Standard Deviation, Incubation

Journal: PLoS Neglected Tropical Diseases

Article Title: SmSP2: A serine protease secreted by the blood fluke pathogen Schistosoma mansoni with anti-hemostatic properties

doi: 10.1371/journal.pntd.0006446

Figure Lengend Snippet: Preparation of recombinant SmSP2 and identification of native SmSP2. (A) The recombinant protease domain of SmSP2 (rSmSP2) expressed in P . pastoris was resolved by SDS-PAGE and protein-stained or visualized by polyclonal anti-rSmSP2 IgG. For in-gel activity-based labeling, rSmSP2 was incubated with the fluorescent active site probe, BoRC, resolved by SDS-PAGE and visualized using a fluorescence scanner. The competitive labeling was performed with the serine protease inhibitor, Pefabloc SC. (B) Protein extracts of S . mansoni adult worms and their ESP were resolved by SDS-PAGE and visualized by the anti-rSmSP2 IgG.

Article Snippet: The competitive labeling reaction was also performed after treatment of SmSP2 for 15 min at 37°C with 1 mM serine protease inhibitor Pefabloc SC (Sigma-Aldrich).

Techniques: Recombinant, SDS Page, Staining, Activity Assay, Labeling, Incubation, Fluorescence, Protease Inhibitor, End-sequence Profiling

Journal: Antimicrobial Agents and Chemotherapy

Article Title: Mutations Conferring Resistance to a Potent Hepatitis C Virus Serine Protease Inhibitor In Vitro

doi: 10.1128/AAC.48.6.2260-2266.2004

Figure Lengend Snippet: Three-dimensional structure of the BILN 2061 binding site of HCV protease. (A) Protein backbone structure of the HCV NS3 protein showing the separate helicase and protease domains in orange. BILN 2061 is colored green, and the alpha carbons of the mutant residues are shown as large blue balls. The sequence corresponding to the NS4A peptide is colored black. (B) Close-up view showing BILN 2061 (carbon, green; oxygen, red; nitrogen, blue) within the active site of HCV NS3 protease and the three nearby mutating residues.

Article Snippet: BILN 2061 is a novel, specific hepatitis C virus (HCV) NS3 serine protease inhibitor discovered by Boehringer Ingelheim that has shown potent activity against HCV replicons in tissue culture and is currently under clinical investigation for the treatment of HCV infection.

Techniques: Binding Assay, Mutagenesis, Sequencing