Characterization of MdpS: an in-depth analysis of a MUC5B-degrading protease from Streptococcus oralis

• DOI: 10.3389/fmicb.2024.1340109
• Publication Date: 2024-01-18T04:44:45Z
• Authors: Fredrik Leo; Rolf Lood; Kristina A. Thomsson; Jonas Nilsson; Gunnel Svensäter; Claes Wickström
• Keywords: Streptococcus oralis; Tooth surface

Oral biofilms, comprising hundreds of bacteria and other microorganisms on oral mucosal dental surfaces, play a central role in health disease dynamics. Streptococcus oralis , key constituent these contributes significantly to the formation which, serving as an early colonizer microcolony scaffold. The interaction between S. orally predominant mucin, MUC5B, is pivotal biofilm development, yet mechanism underlying MUC5B degradation remains poorly understood. This study introduces MdpS (Mucin Degrading Protease from ), protease that extensively hydrolyses offers insight into its evolutionary conservation, physicochemical properties, substrate- amino acid specificity. exhibits high sequence conservation within species also explicitly among colonizing streptococci. It calcium or magnesium dependent serine with strict preferences, including narrow pH temperature tolerance, sensitivity increasing concentrations sodium chloride reducing agents. Furthermore, primarily hydrolyzes proteins O-glycans, but shows activity toward immunoglobulins IgA1/2 IgM, suggesting potential immunomodulatory effects. Significantly, degrades N- C-terminal domains, emphasizing mucin degradation, implications for carbon nitrogen sequestration cross-feeding. Moreover, depending substrate glycosylation, acids serine, threonine cysteine triggers enzymatic action. Understanding interplay facilitated by MdpS, has significant management healthy eubiotic microenvironment, offering targets interventions aimed at modulating composition succession. Additionally, since does not rely O-glycan removal prior extensive peptide backbone hydrolysis, data challenges current model degradation. These findings emphasize necessity further research this field.