ABSTRACT
Through protein-protein BLAST of homologous sequences in different species in NCBI database and preliminary simulating molecular docking and molecular dynamics by computer software discovery studio 3.1, three amino acids R25K26K27 of natural human parathyroid hormone (1-34) with Q25E26L27 were mutated and the biological activity of the mutant peptide was evaluated. Result showed that: root mean superposition deviation RMSD value between PTH (1-34)-(RKK-QEL) and PTH (1-34) peptide main chain was 2.509 3, indicating that the differences between the two main chain structural conformation was relatively small; the interaction energy between PTH (1-34)-(RKK-QEL) and its receptor protein PTH1R had been enhanced by 7.5% compared to nature PTH (1-34), from -554.083 kcal x mol(-1) to -599.253 kcal x mol(-1); the number of hydrogen bonds was increased from 32 to 38; PTH (1-34)-(RKK-QEL) can significantly stimulate the RANKL gene expression (P < 0.01) while inhibiting the OPG gene expression (P < 0.01) in UAMS-32P cells; in the co-culture system of UAMS-32P cells and mouse primary femur bone marrow cells, PTH (1-34)-(RKK-QEL) stimulated the formation of osteoclasts (P < 0.01) and had a higher biological activity than PTH (1-34) standard reagents.
ABSTRACT
A double antibody sandwich ELISA for quantitative analysis of recombinant fusion protein IL-2-HSA was constructed using a polyclonal antibody to human IL-2 for capture and a monoclonal antibody to HSA with HRP-labeled conjugate for detection.The optimal concentration of the first coating antibody and detection antibody were 2 μg/mL and 0.5 μg/mL,respectively.Regression equation of the linear calibration curve was:y = 0.442 9 x-1.143 3 with a correlation coefficient of 0.996 6,and the linear detection ranged from 39.06 ng/mL to 1 250 ng/mL.Recovery from the supernatant of fermentation broth was 98.13% to 102.94%.The specificity assay indicated that it had little cross-reactions with IL-2 and HSA.The soundness analysis suggested that fermentation broth,mouse serum and dilution had no influence on the method.The present method can be used in the studies on fermentation,purification and clinical diagnosis.
ABSTRACT
In order to obtain enough fusion protein for developing preclinical studies of IFNbeta-HAS, we screened Pichia pastoris transformants expressing high-level protein by immunology method. The yield of IFNbeta-HSA was about 500 mg/L by fed-batch fermentation. The purity of IFNbeta-HSA reached 96% through the steps of ultrafiltration, Blue Sepharose FF, Ni2+-IMAC and DEAE Sepharose FF. Analysis of Western blotting showed that IFNbeta-HSA had the antigenicity of IFNbeta and HSA. The specific activity was about 1.96 x 10(7) IU/mg by standard survival activity test on WISH cells challenged with VSV virus. This study provided a method to produce IFNbeta-HSA.
Subject(s)
Humans , Fermentation , Interferon-beta , Genetics , Pichia , Genetics , Metabolism , Recombinant Fusion Proteins , Genetics , Serum Albumin , GeneticsABSTRACT
Aim To develop a model for screening DPPIV inhibitor from Chinese Herbal medicine.Methods With Gly-Pro-PNA as a substrate,DPPIV activity was assayed by the chromogenic substrate.The concentration of DPPIV and Gly-Pro-PNA,temperature,pH and reaction time were optimized.Results The optimal enzymatic reaction system was as follows:DPPIV 0.5 U?L-1,Gly-Pro-PNA 0.262 ?mol?L-1,37℃,pH 8.2,reaction for 60 min.Further more,many kinds of herbal abstracts were screened and some had the DPPIV inhibitory function,such as Leech,Poria cum Radix Pini and Buddleja officinalis Maxim.Conclusion The model can be used to screen for DPPIV inhibitors in vitro.