ABSTRACT
In order to produce recombinant human anti-HBsAg Fab antibody in Pichia pastoris, the recombinant yeast was fermented using fed-batch system in a 30 L bioreactor. The fermentation temperature was 30 degrees C, the pH was 5.0 approximately 5.3, and the DO was 20% approximately 30%. The recombinant Fab antibody was purified from crude culture supernatant by ion exchange and analyzed by SDS-PAGE and western blot and ELISA. When the absorbance (OD600) of broth reach 300 at the end of fed-batch phase, the induced phase was initiated. The results showed that recombinant human anti-HBsAg Fab antibody was high-level expressed in recombinant Pichia pastoris using a fed-batch fermentation system. Both chains of the Fab were successfully expressed upon methanol induction. After 192 h of induction, the expression level of recombinant Fab (soluble) reached 412 mg/L. The recombinant Fab antibody was purified effectively by ion-exchange chromatography from the fermentation supernatant to a purity of 95%. And the affinity activities of the purified recombinant Fab antibdy and fermentation supernatant were detected, and both of them showed high affinity activities. The results demonstrated that recombinant human anti-HBsAg Fab antibody could be high level produced by fed-batch fermentations in Pichia pastoris. Which can be efficiently used in industrial production.
Subject(s)
Humans , Fermentation , Hepatitis B Antibodies , Hepatitis B Surface Antigens , Allergy and Immunology , Immunoglobulin Fab Fragments , Pichia , Genetics , Recombinant ProteinsABSTRACT
<p><b>OBJECTIVE</b>Despite the causes for melanin increase, the increased gene expression of TYR is a common pathological process. Based on this viewpoint, antisense-S-Oligo of TYR was designed and synthesized to regulate synthesis of melanin in order to explore the treatment for skin pigmentation.</p><p><b>METHODS</b>The cultured melanocytes were divided into 3 groups. The group 1 was treated with endothelin, group 2 treated with ultraviolet ray and group 3 was used as the control. In each group, the 5' antisense-S-Oligo, the 3' antisense-S-Oligo, the mixed antisense-S-Oligo of TYR or Dotap only was added. The melanin content and TYR gene expressions were examined.</p><p><b>RESULTS</b>The 5' antisense-S-Oligo, the 3' antisense-S-Oligo and the mixed antisense-S-Oligo significantly inhibited the increase of melanin content and TYR gene expression, which were caused by endothelin or ultraviolet ray treatment. Of the three treatments, the 3' antisense-S-Oligo showed the strongest effect.</p><p><b>CONCLUSION</b>Antisense-S-Oligo has significant regulating effects on TYR gene expression and melanin content. The 3' antisense-S-Oligo is more effective than the 5' antisense-S-Oligo.</p>
Subject(s)
3' Flanking Region , Genetics , 5' Flanking Region , Genetics , Endothelins , Pharmacology , Gene Expression , Melanins , Melanocytes , Metabolism , Radiation Effects , Oligodeoxyribonucleotides, Antisense , Genetics , Pharmacology , Tyrosine , Genetics , Metabolism , Ultraviolet RaysABSTRACT
Using of two-step integrating technology, transducted the H and L chain gene of humanized Fab fragment of anti-HB-sAg antibody into the genome of methylotropic yeast P. pastoris. Constructed a engineering yeast to produce humanized Fab fragment of the anti-HBsAg antibody. The Fab fragment was efficiently secreted into the medium at a concentration of 50-80 mg/L. The Fab fragment was purified from culturing supernatant of the recombinant yeas by affinity chromatography. The ELISA analysis showed the high affinity of the expressed humanized Fab fragment to the HBsAg.