a dopa decarboxylase modulating the immune response of scallop chlamys farreri多巴脱羧酶调节免疫应答的扇贝斗篷farreri.pdfVIP

A Dopa Decarboxylase Modulating the Immune Response of Scallop Chlamys farreri 1,2 1,2 1 1 1,2 1,2 Zhi Zhou , Jialong Yang , Lingling Wang *, Huan Zhang , Yang Gao , Xiaowei Shi , Mengqiang 1 1,2 1 1 Wang , Pengfei Kong , Limei Qiu , Linsheng Song * 1 Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China, 2 Graduate School, Chinese Academy of Sciences, Beijing, China Abstract Background: Dopa decarboxylase (DDC) is a pyridoxal 5-phosphate (PLP)-dependent enzyme that catalyzes the decarboxylation of L-Dopa to dopamine, and involved in complex neuroendocrine-immune regulatory network. The function for DDC in the immunomodulation remains unclear in invertebrate. Methodology: The full-length cDNA encoding DDC (designated CfDDC) was cloned from mollusc scallop Chlamys farreri. It contained an open reading frame encoding a polypeptide of 560 amino acids. The CfDDC mRNA transcripts could be detected in all the tested tissues, including the immune tissues haemocytes and hepatopancreas. After scallops were treated with LPS stimulation, the mRNA expression level of CfDDC in haemocytes increased significantly (5.5-fold, P,0.05) at 3 h and reached the peak at 12 h (9.8-fold, P,0.05), and then recovered to the baseline level. The recombinant protein of CfDDC (rCfDDC) was expressed in Escherichia coli BL21 (DE3)-Transetta, and 1 mg rCfDDC could catalyze the production of 1.65160.22 ng dopamine within 1 h in vitro. When the haemocytes were incubated wit