Jocelei Maria Chies

Human granulocyte colony stimulating factor (hG-CSF): cloning, overexpression, purification and characterization

BackgroundBiopharmaceutical drugs are mainly recombinant proteins produced by biotechnological tools. The patents of many biopharmaceuticals have expired, and biosimilars are thus currently being developed. Human granulocyte colony stimulating factor (hG-CSF) is a hematopoietic cytokine that acts on cells of the neutrophil lineage causing proliferation and differentiation of committed precursor cells and activation of mature neutrophils. Recombinant hG-CSF has been produced in genetically engineered Escherichia coli (Filgrastim) and successfully used to treat cancer patients suffering from chemotherapy-induced neutropenia. Filgrastim is a 175 amino acid protein, containing an extra N-terminal methionine, which is needed for expression in E. coli. Here we describe a simple and low-cost process that is amenable to scaling-up for the production and purification of homogeneous and active recombinant hG-CSF expressed in E. coli cells.ResultsHere we describe cloning of the human granulocyte colony-stimulating factor coding DNA sequence, protein expression in E. coli BL21(DE3) host cells in the absence of isopropyl-β-D-thiogalactopyranoside (IPTG) induction, efficient isolation and solubilization of inclusion bodies by a multi-step washing procedure, and a purification protocol using a single cationic exchange column. Characterization of homogeneous rhG-CSF by size exclusion and reverse phase chromatography showed similar yields to the standard. The immunoassay and N-terminal sequencing confirmed the identity of rhG-CSF. The biological activity assay, in vivo, showed an equivalent biological effect (109.4%) to the standard reference rhG-CSF. The homogeneous rhG-CSF protein yield was 3.2 mg of bioactive protein per liter of cell culture.ConclusionThe recombinant protein expression in the absence of IPTG induction is advantageous since cost is reduced, and the protein purification protocol using a single chromatographic step should reduce cost even further for large scale production. The physicochemical, immunological and biological analyses showed that this protocol can be useful to develop therapeutic bioproducts. In summary, the combination of different experimental strategies presented here allowed an efficient and cost-effective protocol for rhG-CSF production. These data may be of interest to biopharmaceutical companies interested in developing biosimilars and healthcare community.

Molecular cloning, expression in Escherichia coli and production of bioactive homogeneous recombinant human granulocyte and macrophage colony stimulating factor

Human granulocyte and macrophage colony stimulating factor (hGM-CSF) is a glycoprotein that activates and enhances the differentiation and survival of neutrophils, eosinophils and macrophages, which play a key role in the innate immune response. Here we describe the construction of the hGM-CSF encoding gene, cloning, expression in Escherichia coli, purification of recombinant hGM-CSF, N-terminal amino acid sequencing, and biological activity assay using TF-1 cells. The results presented show that the combination of experimental strategies employed to obtain recombinant hGM-CSF can yield biologically active protein, and may be useful to scaling-up production of biosimilar protein.

Comparison between Two Erwinia carotovora L-Asparaginase II Constructions: cloning, Heterologous Expression, Purification, and Kinetic Characterization

L-Asparaginase II from Erwinia carotovora may represent an important alternative therapy in the treatment of acute childhood lymphoblastic leukaemia, despite its promising lower glutaminase activity than Escherichia coli and Erwinia chrysanthemi L-asparaginases II, currently used in treatment of this disease. Here we describe cloning, expression, purification and determination of steady-state kinetic parameters for E. carotovora L-asparaginase II: with (AspSP) and without the signal peptide (AspMP). AspMP was purified to homogeneity by a single-step protocol with 91% yield, and AspSP by a two-step protocol with 28% yield. In addition, both enzymes presented similar high specific activities: 208.1 and 237.6 U mg-1, respectively. The Km and kcat values showed that AspMP has lower glutaminase activity than AspSP. Moreover AspMP is produced by a simpler purification protocol, and at higher yield. This process can be amenable to large scale production and be of interest to researchers and biopharmaceutical companies

Human interferon B1 ser17: Coding DNA synthesis, expression, purification and characterization of bioactive recombinant protein

Centro de Pesquisas em Biologia Molecular e Funcional (CPBMF) Instituto Nacional de Ciencia e Tecnologia em Tuberculose (INCT-TB) Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, 90619-900

Production of recombinant β-galactosidase in bioreactors by fed-batch culture using DO-stat and linear control

Abstract β-Galactosidase enzymes continue to play an important role in food and pharmaceutical industries. These enzymes hydrolyze lactose in its constituent monosaccharides, glucose and galactose. The industrial use of enzymes presents an increase in process costs reflecting in higher final product value. An alternative to enhance processes’ productivity and yield would be the use of recombinant enzymes and their large-scale fed-batch production. The overexpression of recombinant β-galactosidase from Kluyveromyces sp. was carried out in 2-L bioreactors using Escherichia coli strain BL21 (DE3) as host. Effect of induction time on recombinant enzyme expression was studied by adding 1 mM isopropyl thiogalactoside (IPTG) at 12 h, 18 h and 24 h of cultivation. Glucose feeding strategies were compared employing feedback-controlled DO-stat and ascendant linear pump feeding in bioreactor fed-batch cultivations. Linear feeding strategy with IPTG addition at 18 h of cultivation resulted in approximately 20 g/L and 17,745 U/L of biomass and β-galactosidase activity, respectively. On the other hand, although the feedback-controlled DO-stat feeding strategy induced at 12 h of cultivation led to lower final biomass of 18 g/L, it presented an approximately 2.5 increase in enzymatic activity, resulting in 42,367 U/L, and most importantly it led to the most prominent specific enzymatic activity of approximately 40 U/mgprotein. Comparing to previous results, these results suggest that the DO-stat feeding is a promising strategy for recombinant β-galactosidase enzyme production.