Quantifying the Kinetics of Pilus-Specific Sortase-Catalyzed Crosslinking Using High-Performance Liquid...

Area of Science:

• Microbiology
• Biochemistry
• Enzymology

Background:

• Gram-positive bacteria utilize pili for adhesion and other functions.
• Pilus protein components (pilins) are crosslinked by pilus-specific sortase enzymes.
• Sortases catalyze transpeptidation, forming lysine isopeptide bonds essential for pilus structure.

Purpose of the Study:

• To present a protocol for measuring the kinetics of pilus-specific sortase (SrtA) activity.
• To enable quantitative analysis of sortase-mediated pilus crosslinking.
• To provide a method applicable to various pilus-specific sortases.

Main Methods:

• Reconstitution of the SpaA pilus crosslinking reaction in vitro.
• Utilizing high-performance liquid chromatography (HPLC) to monitor reaction kinetics.
• Developing a biochemical procedure for sortase activity measurement.

Main Results:

• A robust protocol for measuring ^CdSrtA-catalyzed pilus crosslinking kinetics was established.
• The method allows for quantitative assessment of sortase enzyme activity.
• The presented biochemical procedure is adaptable for studying other pilus-specific sortases.

Conclusions:

• The developed HPLC-based protocol provides a reliable method for studying sortase enzyme kinetics.
• This technique facilitates a deeper understanding of bacterial pilus assembly mechanisms.
• The protocol's versatility supports broader research into sortase functions in Gram-positive bacteria.