The effect of plasma gelsolin on actin filaments. Ca2+-dependency of the capping and severing activities

The Ca2+-dependency of plasma gelsolin capping and severing properties was investigated using viscometry, fluorescence of N-(1-pyrenyliodoacetamide)-labelled actin and Triton X-100 cell models. The two properties of plasma gelsolin appear to be expressed differently, severing being fully Ca2+-dependent, whereas capping seems to take place, even in the absence of Ca2+, although less efficiently.