N-Terminal Nonrepetitive Domain Common to Dragline, Flagelliform, and Cylindriform Spider Silk Proteins

作者：Anna Rising, Göran Hjälm, Wilhelm Engström, Jan Johansson · 发表于：Biomacromolecules · 年份：2006 · DOI：10.1021/bm060693x · 被引用次数：143 · 研究领域：Silk-based biomaterials and applications、Biochemical and Structural Characterization、Antimicrobial Peptides and Activities

Spider silk has been extensively studied for its outstanding mechanical properties. Partial intermediate and C-terminal sequences of different spider silk proteins have been determined, and during the past decade also N-terminal domains have been characterized. However, only some of these N-terminal domains have been reported to contain signal peptides, leaving the mechanism whereby they enter the secretory pathway open to speculation. Here we present the sequence of a 394-residue N-terminal region of the Euprosthenops australis major ampullate spidroin 1 (MaSp1). A close comparison with published sequences from other species revealed the presence of N-terminal signal peptides followed by an approximately 130-residue nonrepetitive domain. From secondary structure predictions, helical wheel analysis, and circular dichroism spectroscopy this domain is concluded to contain five alpha-helices and is a conserved constituent of hitherto analyzed dragline, flagelliform, and cylindriform spider silk proteins.