Journal: International Journal of Molecular Sciences

Article Title: Epithelial PCSK6 Promotes Proliferation and Decreases Collagen Deposition by Fibroblasts Potentially via MMP Activation

doi: 10.3390/ijms27115104

Figure Lengend Snippet: PCSK6 promotes MMP activation. ( A ) Proteolytic activity of CM from mCherry-control, PCSK6-high and PCSK6-low A549 cells on the fluorogenic MMP substrate peptide {Mca}-Lys-Pro-Leu-Gly-Leu-{Dap(Dnp)}-Ala-Arg-NH2 ( n = 3). ( B ) Proteolytic activity of CM from mCherry-control, PCSK6-high and PCSK6-low A549 cells on the fluorogenic MMP14 substrate peptide MCA-PLA-C(OMeBz)-WAR(Dpa)-NH 2 ( n = 3). ( C ) Proteolytic activity of CM from mCherry-control, PCSK6-high and PCSK6-low A549 cells collected in the presence or absence of 50 µM furin convertase inhibitor (FC inh) on the fluorogenic MMP substrate peptide ( n = 3). ( D ) Proteolytic activity of CM from mCherry-control, PCSK6-high and PCSK6-low A549 cells collected in the presence or absence of 50 µM furin convertase inhibitor (FC inh) on the fluorogenic MMP14 substrate peptide ( n = 3). ( E – G ) Proteolytic activity of CM from mCherry-control, PCSK6-high and PCSK6-low A549 cells in the presence or absence of 500 µM broad-spectrum MMP inhibitor GM6001 ( E ), 50 µM Marimastat ( F ) or the combination of GM6001 and Marimastat ( G ). Fluorescence was measured at excitation 320/20 nm, emission 360/40 nm and normalized to the baseline fluorescence of the substrate peptide in the medium alone. MFI indicates mean channel fluorescence minus background. Data are expressed as mean ± SEM. Statistical significance was tested using mixed-effects analysis with Tukey’s post hoc test for multiple comparisons, and significance is shown relative to the indicated groups. p -values: * <0.05, ** <0.01, *** <0.001 and **** <0.0001.

Article Snippet: MMP activity was assessed using a fluorogenic MMP substrate peptide (CAS 720710-69-0, MCE, Monmouth Junction, NJ, USA), in the presence or absence of the broad-spectrum MMP inhibitor GM6001 (sc-203979, Santa Cruz Biotechnology) or Marimastat (CAS 154039-60-8, MCE).

Techniques: Activation Assay, Activity Assay, Control, Fluorescence

Journal: bioRxiv

Article Title: Discovery, characterisation and optimisation of bicyclic peptide inhibitors that disarm Staphylococcus aureus α-hemolysin

doi: 10.64898/2026.03.09.710508

Figure Lengend Snippet: a) Alexa Fluor 647-labeled AhlyH35A (7.5nM) was incubated with A549 cells in the presence of increasing concentrations of Peptide 88 or a control bicyclic peptide. Cell-associated fluorescence was quantified by flow cytometry and shown as histogram overlays. Negative control (cells only) shown in black; positive control (AhlyH35A without peptide) shown in red. b) Quantification of median fluorescence intensity plotted against peptide concentration. Data are normalized to the negative and positive controls. c) ADAM10 protease activation by Ahly (6µM) was measured using a whole-cell FRET peptide cleavage assay in the presence of Peptide 88 or a control bicyclic peptide (900µM). Mean of two biological replicates; error bars indicate standard deviation. Data were analysed using one-way ANOVA with Dunnett’s test: ns = not significant; ** = P < 0.01.

Article Snippet: Following incubation, cells were washed once with 25mM Tris buffer, pH 8.0 and a fluorogenic ADAM10 substrate peptide (Mca-PLAQAV-Dpa-RSSSR-NH 2 ; R&D Systems) was added at a final concentration of 10μM.

Techniques: Labeling, Incubation, Control, Fluorescence, Flow Cytometry, Negative Control, Positive Control, Concentration Assay, Activation Assay, Cleavage Assay, Standard Deviation