A chicken intestinal tract Beta-
defensin cDNA is characterized in that the cDNA has the following sequence: tcagacagcc agctgtgcag gaacaaccat ggccactgcc ggaggctctg cttccacatg gagagctggg ctgggagctg catgaacggc cgcctgcgct gctgcaggtt ctccaccaag cagccctttt ccaaccctaa acattcagtg ctgcacacag cagagcagga cccttcccca agccttggag ggacgtga. The
amino acid sequence of the Beta-
defensin is Ser-Asp-Ser-Gln-Leu Cys-Arg-Asn-Asn-His Gly-His-Cys-Arg- Arg Leu-Cys-Phe-His-Met Glu- Ser-Trp-Ala-Gly Ser-Cys-Met-Asn-Gly Arg-Leu-Arg-Cys-Cys Arg-Phe-Ser-Thr-Lys-Gln Pro-Phe-Ser-Asn-Pro Lys-His-Ser-Val-Leu His-Thr-Ala-Glu-Gln Asp-Pro-Ser-Pro-Ser Leu-Gly-Gly-Thr. The extraction method comprises the following steps of: (1) collecting broken mucosa cells of chicken intestinal tract; (2) breaking vesicles; (3) leaching with 5%
acetic acid under stirring, centrifuging, collecting supernatant, removing
sediment, subpackaging the supernatant and freeze-storing to obtain crude chicken intestinal tract Beta-
defensin; (4) separating the supernatant with
Sephadex G-100 gel column at low temperature, eluting with 0.2mol / L
sodium acetate (constant flow pump speed 3*1), detecting with
nucleic acid-
protein detector, collecting the eluate with an automatic collector (1.5mL each tube), and recording with a recorder (speed 6cm / h, and range 20mV); (5) detecting the
antibacterial activity of the liquid in each tube to
Pasteurella with
agarose diffusion method, collecting the eluate with bacteriostatic activity, and storing under vacuum
freeze drying; (6) purifying the the eluate with bacteriostatic activity with
Tricine-PAGE, PVDF membrane blotting the
protein bands, and performing
amino acid sequence analysis with Sanger
partial hydrolysis method; and (7) deriving chicken intestinal tract Beta-defensin cDNA with BLAST
software.