Signal peptide of human nerve growth factor is better than signal peptide of mouse nerve growth factor in mediating secretory expression of beta-endorphin / 第二军医大学学报

ABSTRACT

Objective:To clarify whether the signal peptide of human nerve growth factor can mediate secretory expression of beta-endorphin and whether there is difference between the efficiency of signal peptides from human and mouse nerve growth factor.Methods: Two kinds of eukaryotic vectors containing human or mouse signal sequence-mediated secretory expression of beta-endorphin were constructed.The culture supernatant and cells were collected 48 h after NIH3T3 cells were transfected by the two kinds of vectors,and the cover slips with single-layer cells was prepared.The concentration of beta-endorphin in the culture was determined by radio-immunoassay.The total RNA was extracted from cells and mRNA from fusion genes was assayed by RT-PCR.Cells on cover slips were subjected to immunofluorescence staining.Results: RT-PCR showed that the fusion genes were expressed in NIH3T3 cells;the expression of beta-endorphin was mainly in the cytoplasm of NIH3T3 cells.The concentrations of beta-endorphin in the supernatants 48 h after transfection with pcDNA3.1-hEP and pcDNA3.1-mEP were(280.33?24.16) pg/ml and(191.04?7.96) pg/ml(P