Detection of Fibronectin-Binding Proteins of Streptococcus pyogenes Using Ligand Blot Analysis

Abstract

Streptococcus pyogenes utilizes extracellular cellular matrix (ECM) proteins to adhere to human tissues and internalize into host cells. Fibronectin (Fn) is one of the most abundant ECM proteins and targeted by a wide variety of secreted Fn-binding proteins (Fbps) of S. pyogenes. However, prior to detailed kinetic analysis of that binding process, evaluations of the ability of S. pyogenes strains to bind to Fn as well as interactions of target molecules with Fn are required. In this chapter, we present routine procedures for ligand blot analysis with labeled human Fn, using bacterial cell wall extracts prepared by either enzymatic digestion of cells or extraction with a denaturing agent.