中国对虾抗菌肽成熟肽的cDNA克隆

Molecular Cloning of the Cdna Encoding a Mature Antimicrobial Peptide from Shrimp,Penaeus Chinensis

利用RT -PCR、嵌套PCR(NestedPCR)和 3′ -RACE等方法 ,从中国对虾血细胞中克隆到 1种抗菌肽基因片段 ,称为中国对虾肽 (Chp)基因 .此基因片段长 5 4 3bp ,开读框共有 15 6个碱基 ,编码 5 2个氨基酸 .该基因所编码的氨基酸序列对应于凡那对虾抗菌肽成熟肽的序列 ,与其一致性为5 2 - 5 9% ,相似性为 61- 73% ,分子量为 5 65 2 .4Da ,理论等电点为 9.76,带正点荷的氨基酸 (Arg -Lys)为 8个 ,不含带负电荷的氨基酸 .上述这些特征 (分子量较小 ,带正点荷 )均为抗菌肽的普遍特征 .

We have cloned a new gene fragment of an antimicrobial peptide,mature ch-penaeidin gene,from the hemocyte cDNAs of the Chinese shrimp,Penaeus chinensis,by RT-PCR,Nested PCR and 3'-RACE methods.The nucleotide sequence of the fragment,ch-penaeidin,consists of 543bp,and has open reading frame of 156bp.Encoding 52 amino acid residues.The deduced amino acid sequence of putative showed 52-59% amino acide sequence identity with that of penaeidin from Litopenaus vannamei,lv-penaeidins.Sequence comparison showed that ch-penaeidin is similar to lv-penaeidins 3C(73%).The molecular mass of the ch-penaeidin is 5652.4Da,theoretical pI 9.76.It has 8 positively charged residues(Arg+Lys),and no negatively charged one.