Optimizing proinsulin production in E. coli BL21 (DE3) using taguchi method and efficient one-step insulin purification by on-column enzymatic cleavage.

Diabetes is a critical worldwide health problem. Numerous studies have focused on producing recombinant human insulin to address this issue. In this research, the process factors of production of recombinant His-tagged proinsulin in E.

Signal amplification of a quartz crystal microbalance immunosensor by gold nanoparticles-polyethyleneimine for hepatitis B biomarker detection.

The procedures currently used for hepatitis B (HB) detection are not suitable for screening, clinical diagnosis, and point-of-care testing (POCT). Therefore, we developed and tested a QCM-based immunosensor by surface modification with AuNP-PEIs to amplify the signal and provide an oriented-immobilization surface. The AuNP-PEIs were characterized by ICP-Mass, UV/Vis, DLS, FE-SEM, and ATR-FTIR.

A quartz crystal microbalance biosensor based on polyethylenimine-modified gold electrode to detect hepatitis B biomarker.

Biomarkers-based QCM-biosensors are suitable tools for the label-free detection of infectious diseases. In the current study, a QCM-biosensor was developed for the detection of HBsAg. Briefly, anti-HBsAg antibodies were covalently bound to the primary amines after PEI and thiolated-PEI surface modifications of gold-electrode.

Lipopolysaccharide removal affinity matrices based on novel cationic amphiphilic peptides.

Lipopolysaccharide (LPS) is one of the most challenging contaminants in biopharmaceutical industries. Cationic amphiphilic peptides (CAPs) -based affinity matrices can be potent tools for LPS removal in such situations. In this study, two newly designed CAPs derived from the LPS binding site of factor C of horseshoe crab S3E3 and S3E3A were immobilized chemo-selectively on diaminodipropylamine (DADPA) and iodoacetyl functionalized Sepharose beads.

Effect of glutamic acid elimination/substitution on the biological activities of S3 cationic amphiphilic peptides.

Cationic amphiphilic peptides (CAPs) are usually classified as bacterial membrane targeting molecules. Rational design and modification of cationic and amphiphilic properties of CAPs have made them to be used in new medical and biotechnological applications. However, CAPs modification and development strategies are challenging issues due to the risk of cytotoxicity or hemolytic activity.

Production of Erythropoietin-Specific Polyclonal Antibodies.

Background: Erythropoietin, as a principal hormone promotes red blood cell production in bone marrow. Varieties of erythropoietin biosimilar are being produced by recombinant DNA technology in cell cultures. The detection or quantifi cation of these molecules are being performed by diff erent methods which some of theme such as Western blot and enzymelinked immunosorbent assay (ELISA) require specifi c antibodies.

Exploration of Recombinant Streptokinase Degradation Products Under Various pH Reduction Conditions in Downstream Processing.

Background: Methods of producing streptokinase, which can be used in the treatment of myocardial infarction, by hemolytic streptococci and recombinant E. coli have been described in patents since 1955. Degradation products in active pharmaceutical ingredients (APIs) and finished pharmaceutical products are considered as impurities and it is required that these degradation impurities are minimized or rather avoided throughout manufacturing process.

Stability and biological activity evaluations of PEGylated human basic fibroblast growth factor.

Background: Human basic fibroblast growth factor (hBFGF) is a heparin-binding growth factor and stimulates the proliferation of a wide variety of cells and tissues causing survival properties and its stability and biological activity improvements have received much attention.

Materials And Methods: In the present work, hBFGF produced by engineered Escherichia coli and purified by cation exchange and heparin affinity chromatography, was PEGylated under appropriate condition employing 10 kD polyethylene glycol. The PEGylated form was separated by size exclusion chromatography.

Investigation of purification process stresses on erythropoietin peptide mapping profile.

Background: Full compliance of recombinant protein peptide mapping chromatogram with the standard reference material, is one of the most basic quality control tests of biopharmaceuticals. Changing a single amino acid substitution or side chain diversity for a given peptide changes protein hydrophobicity and causes peak shape or retention time alteration in a peptide mapping assay. In this work, the effect of different stresses during the recombinant erythropoietin (EPO) purification process, including pH 4, pH 5, and room temperature were checked on product peptide mapping results.

Effect of post-solubilization conditions on the yield and efficiency of recombinant streptokinase purification at large-scale.

Streptokinase, a plasminogen activator which converts plasminogen to plasmin and consequently promotes fibrinolysis, is the leading drug for treating acute myocardial infarction in developing countries and its production is industrially demanded. In this work, the substantial influence of inclusion body (IB) post-solubilization condition on the performance of a sequential chromatography method for large-scale purification of recombinant streptokinase was demonstrated. In the preliminary experiments, various post-solubilization pH conditions were studied, and it was shown that the pH value of solubilized inclusion bodies (i.