title: Structural characterization of the major ampullate silk spidroin-2 protein produced by the spider Nephila clavipes.
abstract: Major ampullate spidroin-2 (MaSp2) is one of the most important spider silk protein, but up to now no information is available regarding the post-translational modifications (PTMs) of this protein. A gel-based mass spectrometry strategy using collision-induced dissociation (CID) and electron-transfer dissociation (ETD) fragmentation methods was used to sequence Nephila clavipes MaSp2 (including the N- and C-terminal non-repetitive domains, and the great part of the central core), and to assign a series of post-translational modifications (PTMs) on to the MaSp2 sequence. Two forms of this protein were identified, with different levels of phosphorylation along their sequences. These findings provide a basis for understanding mechanoelastic properties and can support the future design of recombinant spider silk proteins for biotechnological applications.
authors.affiliation: Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University, Rio Claro, SP 13500, Brazil; Department of Pharmaceutical Chemistry, University of Vienna, Vienna 1090, Austria.
authors.forename: José Roberto Aparecido Dos
authors.initials: JR
authors.lastname: Santos-Pinto
authors.affiliation: Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University, Rio Claro, SP 13500, Brazil.
authors.forename: Helen Andrade
authors.initials: HA
authors.lastname: Arcuri
authors.affiliation: Department of Pharmaceutical Chemistry, University of Vienna, Vienna 1090, Austria. Electronic address: gert.lubec@univie.ac.at.
authors.forename: Gert
authors.initials: G
authors.lastname: Lubec
authors.affiliation: Center of the Study of Social Insects, Department of Biology, Institute of Biosciences of Rio Claro, São Paulo State University, Rio Claro, SP 13500, Brazil. Electronic address: mspalma@rc.unesp.br.
authors.forename: Mario Sergio
authors.initials: MS
authors.lastname: Palma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000378:metabolism*; D005349:Fibroins / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D010766:Phosphorylation / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000502:physiology; D011994:Recombinant Proteins / Q000378:metabolism; D016415:Sequence Alignment; D047011:Silk / Q000378:metabolism*; D013112:Spiders / Q000378:metabolism*
chemical_list: D060829:Arthropod Proteins; D011994:Recombinant Proteins; D047011:Silk; C076815:spidroin 2; D005349:Fibroins
keywords: Mass spectrometry; Nephila clavipes; Phosphorylation; Post-translational modification; Silk proteins