Journal: Frontiers in Cellular and Infection Microbiology

Article Title: Porphyromonas endodontalis HmuY differentially participates in heme acquisition compared to the Porphyromonas gingivalis and Tannerella forsythia hemophore-like proteins

doi: 10.3389/fcimb.2024.1421018

Figure Lengend Snippet: Comparison of the proteolytic activity of P. endodontalis and P. gingivalis . (A) Total proteolytic activity in whole bacterial cultures (iron- and heme-rich medium; Hm medium) was determined using azocasein as a substrate. The activity is shown as an increase in absorbance at 450 nm (A 450 ) caused by the release of a colored product within 60 minutes by 1 ml of bacterial culture with an optical density at 600 nm of 1. (B) Susceptibility of human hemoproteins and selected HmuY proteins to degradation by proteases produced by P. endodontalis or P. gingivalis . Purified proteins were added to the bacterial cultures (Hm medium) at a final 2 µM concentration, samples were incubated, collected at the indicated time points, and analyzed by SDS-PAGE and CBB G-250 staining. As a control, Hm medium alone was used instead of bacterial cultures. (C) Protein pattern of P. gingivalis or P. endodontalis proteins in iron- and heme-rich culture medium (Hm medium) without adding host hemoproteins or HmuY proteins. metHb, methemoglobin; HSA, serum albumin; Hpx, hemopexin; HmuY Pg , P. gingivalis HmuY; HmuY Pe , P. endodontalis HmuY homolog; HmuY Tf , T. forsythia HmuY homolog; M, protein molecular mass markers. **** P <0.0001.

Article Snippet: Except for methemoglobin (metHb; Sigma-Aldrich), protein-heme complexes were prepared by mixing protein and heme at a 1:1.2 molar ratio and incubation at room temperature for 1 hour.

Techniques: Comparison, Activity Assay, Produced, Purification, Concentration Assay, Incubation, SDS Page, Staining