Abstract: The aggregate sticky glue (ASG) secreted by spider can form into very sticky droplets using for prey capture. As one component of ASG, ASG2 has been proved is a spidroin, which has the potential as a new type biomaterial for its unique material properties. At present, there are few researches about the C-terminal domain (CT) of the ASG2 which restricts the use of the ASG2. The sequence (AvAGS2CT) of the C-terminal domain of the ASG2 from Araneus ventricosus was firstly obtained via the single primer PCR based on the genomic DNA. And the AvAGS2CT was further cloned, expressed and purified with the finally yield of 75 mg/L; meanwhile, at the first time, the secondary structure of the AvAGS2CT protein was analyzed by the CD spectra, which indicated that the α-helix is its predominant secondary structure. These results provide useful information for the CT structural and functional analysis of ASG2.

Key words: ASG2, C-terminal domain, single primer PCR, cloning and expression, secondary structure