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Capping and dynamic relation between domains 1 and 2 of gelsolin
Author(s) -
Feinberg Jeanne,
Kwiatek Olivier,
Astier Catherine,
Diennet Severine,
Mery Jean,
Heitz Fréderic,
Benyamin Yves,
Roustan Claude
Publication year - 1998
Publication title -
journal of peptide science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 66
eISSN - 1099-1387
pISSN - 1075-2617
DOI - 10.1002/(sici)1099-1387(199804)4:2<116::aid-psc135>3.0.co;2-r
Subject(s) - gelsolin , actin , peptide , chemistry , actin binding protein , biophysics , actina , sequence (biology) , nucleation , protein filament , molecule , binding site , biochemistry , actin cytoskeleton , biology , cytoskeleton , cell , organic chemistry
Gelsolin is a protein that severs and caps actin filaments. The two activities are located in the N‐terminal half of the gelsolin molecules. Severing and subsequent capping requires the binding of domains 2 and 3 (S2–3) to the side of the filaments to position the N‐terminal domain 1 (S1) at the barbed end of actin (actin subdomains 1 and 3). The results provide a structural basis for the gelsolin capping mechanism. The effects of a synthetic peptide derived from the sequence of a binding site located in gelsolin S2 on actin properties have been studied. CD and IR spectra indicate that this peptide presented a secondary structure in solution which would be similar to that expected for the native full length gelsolin molecule. The binding of the synthetic peptide induces conformational changes in actin subdomain 1 and actin oligomerization. An increase in the polymerization rate was observed, which could be attributed to a nucleation kinetics effect. The combined effects of two gelsolin fragments, the synthetic peptide derived from an S2 sequence and the purified segment 1 (S1), were also investigated as a molecule model. The two fragments induced nucleation enhancement and inhibited actin depolymerization, two characteristic properties of capping. In conclusion, for the first time it is reported that the binding of a small synthetic fragment is sufficient to promote efficient capping by S1 at the barbed end of actin filaments. ©1998 European Peptide Society and John Wiley & Sons, Ltd.