The F-Actin family of capping proteins includes CapZ-(alpha)1, CapZ-(alpha)2, CapZ-(alpha)3 and CapZ-(beta)3, all of which function in a calcium-dependent manner and bind to the fast growing barbed end of Actin filaments, thereby blocking protein exchange at these ends. The F-Actin capping protein complex is a heterodimer consisting of (alpha) and (beta) subunits that caps the barbed ends of Actin filaments and nucleates the polymerization of Actin monomers, yet does not sever Actin filaments. CapZ-(alpha)1, also known as F-Actin-capping protein subunit alpha-1, is a 286 amino acid subunit of the heterodimer that forms the F-Actin capping protein complex. CapZ-(alpha)1 also has been shown to bind S-100 (beta) chain, a signaling molecule involved in the calcium-sensitive assembly of intermediate filaments that has been linked to Alzheimer's disease.