Aparecido dos Santos-Pinto, Jose Roberto [UNESP]Arcuri, Helen Andrade [UNESP]Priewalder, HelgaSalles, Heliana Clara [UNESP]Palma, Mario Sergio [UNESP]Lubec, Gert2018-11-262018-11-262015-09-01Journal Of Proteome Research. Washington: Amer Chemical Soc, v. 14, n. 9, p. 3859-3870, 2015.1535-3893http://hdl.handle.net/11449/160797Most reports about the 3-D structure of spidroin-1 have been proposed for the protein in solid state or for individual domains of these proteins. A gel-based mass spectrometry strategy using collision-induced dissociation (CID) and electron-transfer dissociation (ETD) fragmentation methods was used to completely sequence spidroins-1A and -1B and to assign a series of post-translational modifications (PTMs) on to the spidroin sequences. A total of 15 and 16 phosphorylation sites were detected on spidroin-1A and -1B, respectively. In this work, we present the nearly complete amino acid sequence of spidroin-1A and -1B, including the nonrepetitive N- and C-terminal domains and a highly repetitive central core. We also described a fatty acid layer surrounding the protein fibers and PTMs in the sequences of spidroin-1A and -1B, including phosphorylation. Thus, molecular models for phosphorylated spidroins were proposed in the presence of a mixture fatty acids/water (1:1) and submitted to molecular dynamics simulation. The resulting models presented high content of coils, a higher percentage of alpha-helix, and an almost neglected content of 3(10)-helix than the previous models. Knowledge of the complete structure of spidroins-1A and -1B would help to explain the mechanical features of silk fibers. The results of the current investigation provide a foundation for biophysical studies of the mechanoelastic properties of web-silk proteins.3859-3870engsilk proteinsNephila clavipesmass spectrometrypost-translational modificationmolecular dynamicsArtigo10.1021/acs.jproteome.5b00243WOS:000361087100039Acesso restrito2901888624506535