Calpastatin is an inhibitor of calpain (calcium-activated intracellular cysteine protease). Calpastatin regulates calpain by inhibiting both the proteolytic activity of Calpain and its binding to membranes. Calpastatin exists in two types, tissue type and erythrocyte type, resulting from both alternative splicing and proteolytic processing. Calpastatin co-localizes with human leukocyte antigen-DR (HLA-DR) on activated microglia in the aging brain. Calpain influences the process of spermatogenesis and the events preceding fertilization, such as the acrosome reaction. Primary antibodies are available purified, or with a selection of fluorescent CF Dyes and other labels. CF Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF405S and CF405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.
