Whereas the interaction of the N-terminal domain of gelsolin with monomeric actin is well known, the location of domains 2-3 interacting with the actin filament during the severing process remains uncertain. In this study we define an interface that supports binding of gelsolin domain 2 along the filament axis. Using specific antibodies and actin peptides, this interface was restricted to two adjacent segments: 1-10 and 18-28 in the N-terminal part of actin sequence.