scholarly journals Synthesis of Human Bone Morphogenetic Protein-2 (hBMP-2) in E. coli Periplasmic Space: Its Characterization and Preclinical Testing

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3525
Author(s):  
João E. Oliveira ◽  
Miriam F. Suzuki ◽  
Renata Damiani ◽  
Eliana R. Lima ◽  
Kleicy C. Amaral ◽  
...  
Keyword(s):  
High Performance ◽  
Osmotic Shock ◽  
Cytoplasmic Inclusion ◽  
Reversed Phase ◽  
C2c12 Cells ◽  
Size Exclusion ◽  
Bone Morphogenetic Protein 2 ◽  
E Coli

Human BMP-2, a homodimeric protein that belongs to the TGF- β family, is a recognized osteoinductor due to its capacity of inducing bone regeneration and ectopic bone formation. The administration of its recombinant form is an alternative to autologous bone grafting. A variety of E. coli-derived hBMP-2 has been synthesized through refolding of cytoplasmic inclusion bodies. The present work reports the synthesis, purification, and characterization of periplasmic hBMP-2, obtained directly in its correctly folded and authentic form, i.e., without the initial methionine typical of the cytoplasmic product that can induce undesired immunoreactivity. A bacterial expression vector was constructed including the DsbA signal peptide and the cDNA of hBMP-2. The periplasmic fluid was extracted by osmotic shock and analyzed via SDS-PAGE, Western blotting, and reversed-phase high-performance liquid chromatography (RP-HPLC). The purification was carried out by heparin affinity chromatography, followed by high-performance size-exclusion chromatography (HPSEC). HPSEC was used for qualitative and quantitative analysis of the final product, which showed >95% purity. The classical in vitro bioassay based on the induction of alkaline phosphatase activity in myoblastic murine C2C12 cells and the in vivo bioassay consisting of treating calvarial critical-size defects in rats confirmed its bioactivity, which matched the analogous literature data for hBMP-2.

scholarly journals Periplasmic synthesis and purification of the human prolactin antagonist Δ1-11-G129R-hPRL

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miriam F. Suzuki ◽  
Larissa A. Almeida ◽  
Stephanie A. Pomin ◽  
Felipe D. Silva ◽  
Renan P. Freire ◽  
...  
Keyword(s):  
Size Exclusion Chromatography ◽  
High Performance ◽  
Signal Sequence ◽  
Osmotic Shock ◽  
Size Exclusion ◽  
Specific Expression ◽  
E Coli ◽  
Human Prolactin ◽  
Exclusion Chromatography

AbstractThe human prolactin antagonist Δ1-11-G129R-hPRL is a 21.9 kDa recombinant protein with 188 amino acids that downregulates the proliferation of a variety of cells expressing prolactin receptors. Periplasmic expression of recombinant proteins in E. coli has been considered an option for obtaining a soluble and correctly folded protein, as an alternative to cytoplasmic production. The aim of this work was, therefore, to synthesize for the first time, the Δ1-11-G129R-hPRL antagonist, testing different activation temperatures and purifying it by classical chromatographic techniques. E. coli BL21(DE3) strain was transformed with a plasmid based on the pET25b( +) vector, DsbA signal sequence and the antagonist cDNA sequence. Different doses of IPTG were added, activating under different temperatures, and extracting the periplasmic fluid via osmotic shock. The best conditions were achieved by activating at 35 °C for 5 h using 0.4 mM IPTG, which gave a specific expression of 0.157 ± 0.015 μg/mL/A600 at a final optical density of 3.43 ± 0.13 A600. Purification was carried out by nickel-affinity chromatography followed by size-exclusion chromatography, quantification being performed via high-performance size-exclusion chromatography (HPSEC). The prolactin antagonist was characterized by SDS-PAGE, Western blotting, reversed-phase high-performance liquid chromatography (RP-HPLC) and MALDI-TOF–MS. The final product presented > 95% purity and its antagonistic effects were evaluated in vitro in view of potential clinical applications, including inhibition of the proliferation of cancer cells overexpressing the prolactin receptor and specific antidiabetic properties, taking also advantage of the fact that this antagonist was obtained in a soluble and correctly folded form and without an initial methionine.

scholarly journals Periplasmic Synthesis and Purification of the Human Prolactin Antagonist Δ1-11-G129R-hPRL

2021 ◽  
Author(s):  
Miriam Fussae Suzuki ◽  
Larissa Andrade Almeida ◽  
Stephanie Angelo Pomin ◽  
Felipe Douglas Silva ◽  
Renan Passos Freire ◽  
...  
Keyword(s):  
Size Exclusion Chromatography ◽  
High Performance ◽  
Signal Sequence ◽  
Osmotic Shock ◽  
Size Exclusion ◽  
Specific Expression ◽  
E Coli ◽  
Human Prolactin ◽  
Exclusion Chromatography

Abstract The human prolactin antagonist Δ1-11-G129R-hPRL is a 21.9 kDa recombinant protein with 188 amino acids that downregulates the proliferation of a variety of cells expressing prolactin receptors. Periplasmic expression of recombinant proteins in E. coli has been considered an option for obtaining a soluble and correctly folded protein, as an alternative to cytoplasmic production. The aim of this work was, therefore, to synthesize for the first time, the Δ1-11-G129R-hPRL antagonist, testing different activation temperatures and purifying it by classical chromatographic techniques. E. coli BL21(DE3) strain was transformed with a plasmid based on the pET25b(+) vector, DsbA signal sequence and the antagonist cDNA sequence. Different doses of IPTG were added, activating under different temperatures, and extracting the periplasmic fluid via osmotic shock. The best conditions were achieved by activating at 35 °C for 5 h using 0.4 mM IPTG, which gave a specific expression of 0.157±0.015 μg/mL/A600 at a final optical density of 3.43±0.13 A600. Purification was carried out by nickel-affinity chromatography followed by size-exclusion chromatography, quantification being performed via high-performance size-exclusion chromatography (HPSEC). The prolactin antagonist was characterized by SDS-PAGE, Western blotting, reversed-phase high-performance liquid chromatography (RP-HPLC) and MALDI-TOF-MS. The final product presented >95% purity and its antagonistic effects were evaluated in vitro in view of potential clinical applications, including inhibition of the proliferation of cancer cells overexpressing the prolactin receptor and specific antidiabetic properties, taking also advantage of the fact that this antagonist was obtained in a soluble and correctly folded form and without an initial methionine.

scholarly journals On the Conformation of the COOH-terminal Domain of the Large Mechanosensitive Channel MscL

2003 ◽  
Vol 121 (3) ◽  
pp. 227-244 ◽  
Author(s):  
Andriy Anishkin ◽  
Vyacheslav Gendel ◽  
Neda A. Sharifi ◽  
Chien-Sung Chiang ◽  
Lena Shirinian ◽  
...  
Keyword(s):  
Osmotic Shock ◽  
Complete Removal ◽  
Size Exclusion ◽  
Ambient Conditions ◽  
Dynamic Simulations ◽  
E Coli ◽  
Terminal Domain ◽  
Reducing Conditions ◽  
Truncation Mutant

COOH-terminal (S3) domains are conserved within the MscL family of bacterial mechanosensitive channels, but their function remains unclear. The X-ray structure of MscL from Mycobacterium tuberculosis (TbMscL) revealed cytoplasmic domains forming a pentameric bundle (Chang, G., R.H. Spencer, A.T. Lee, M.T. Barclay, and D.C. Rees. 1998. Science. 282:2220–2226). The helices, however, have an unusual orientation in which hydrophobic sidechains face outside while charged residues face inside, possibly due to specific crystallization conditions. Based on the structure of pentameric cartilage protein , we modeled the COOH-terminal region of E. coli MscL to better satisfy the hydrophobicity criteria, with sidechains of conserved aliphatic residues all inside the bundle. Molecular dynamic simulations predicted higher stability for this conformation compared with one modeled after the crystal structure of TbMscL, and suggested distances for disulfide trapping experiments. The single cysteine mutants L121C and I125C formed dimers under ambient conditions and more so in the presence of an oxidant. The double-cysteine mutants, L121C/L122C and L128C/L129C, often cross-link into tetrameric and pentameric structures, consistent with the new model. Patch-clamp examination of these double mutants under moderately oxidizing or reducing conditions indicated that the bundle cross-linking neither prevents the channel from opening nor changes thermodynamic parameters of gating. Destabilization of the bundle by replacing conservative leucines with small polar residues, or complete removal of COOH-terminal domain (Δ110–136 mutation), increased the occupancy of subconducting states but did not change gating parameters substantially. The Δ110–136 truncation mutant was functional in in vivo osmotic shock assays; however, the amount of ATP released into the shock medium was considerably larger than in controls. The data strongly suggest that in contrast to previous gating models (Sukharev, S., M. Betanzos, C.S. Chiang, and H.R. Guy. 2001a. Nature. 409:720–724.), S3 domains are stably associated in both closed and open conformations. The bundle-like assembly of cytoplasmic helices provides stability to the open conformation, and may function as a size-exclusion filter at the cytoplasmic entrance to the MscL pore, preventing loss of essential metabolites.

Xenopus laevis oocytes, eggs and tadpoles contain immunoactive insulin

1994 ◽  
Vol 141 (1) ◽  
pp. 123-129 ◽  
Author(s):  
F de Pablo ◽  
R Dashner ◽  
A R Shuldiner ◽  
J Roth
Keyword(s):  
Xenopus Laevis ◽  
High Performance ◽  
Immunoblot Analysis ◽  
Reversed Phase ◽  
Xenopus Laevis Oocytes ◽  
Maternal Origin ◽  
Insulin Mrna ◽  
Low Levels

Abstract Insulin is a multifunctional polypeptide hormone that regulates metabolic processes and promotes mitogenesis and differentiation in vitro in the cells and tissues of several species. Its role in vivo during embryogenesis is still poorly understood. We have previously found insulin mRNA in mature Xenopus laevis oocytes and in embryos during neurulation (before organogenesis of the pancreas takes place). We have now measured insulin immunoactivity in mature oocytes, unfertilized eggs and day-2 tadpoles. Using reversed phase high performance liquid chromatography, we found low levels of insulin in extracts of oocytes (stage VI). Both Xenopus insulin I and II were detected in unfertilized eggs. The day-2 tadpoles (stages 31–33) also contained immunoactive insulin, and in swimming tadpoles (stage 46) a few clusters of cells containing insulin immunoactivity could be identified by indirect immunofluorescence. Immunoblot analysis was relatively insensitive, detecting insulin only in the adult Xenopus pancreas. In summary, insulin (from maternal origin and embryonic expression) appears to be present early enough in Xenopus laevis to influence developmental processes such as neurulation. Journal of Endocrinology (1994) 141, 123–129

scholarly journals Extension of human GCSF serum half-life by the fusion of albumin binding domain

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Fatemeh Yadavar Nikravesh ◽  
Samira Shirkhani ◽  
Elham Bayat ◽  
Yeganeh Talebkhan ◽  
Esmat Mirabzadeh ◽  
...  
Keyword(s):  
Half Life ◽  
Animal Studies ◽  
Cytoplasmic Inclusion ◽  
Binding Domain ◽  
Size Exclusion ◽  
Albumin Binding ◽  
Exclusion Chromatography ◽  
Aggregation Formation

AbstractGranulocyte colony stimulating factor (GCSF) can decrease mortality of patients undergo chemotherapy through increasing neutrophil counts. Many strategies have been developed to improve its blood circulating time. Albumin binding domain (ABD) was genetically fused to N-terminal end of GCSF encoding sequence and expressed as cytoplasmic inclusion bodies within Escherichia coli. Biological activity of ABD-GCSF protein was assessed by proliferation assay on NFS-60 cells. Physicochemical properties were analyzed through size exclusion chromatography, circular dichroism, intrinsic fluorescence spectroscopy and dynamic light scattering. Pharmacodynamics and pharmacokinetic properties were also investigated in a neutropenic rat model. CD and IFS spectra revealed that ABD fusion to GCSF did not significantly affect the secondary and tertiary structures of the molecule. DLS and SEC results indicated the absence of aggregation formation. EC50 value of the ABD-GCSF in proliferation of NFS-60 cells was 75.76 pg/ml after 72 h in comparison with control GCSF molecules (Filgrastim: 73.1 pg/ml and PEG-Filgrastim: 44.6 pg/ml). Animal studies of ABD-GCSF represented improved serum half-life (9.3 ± 0.7 h) and consequently reduced renal clearance (16.1 ± 1.4 ml/h.kg) in comparison with Filgrastim (1.7 ± 0.1 h). Enhanced neutrophils count following administration of ABD-GCSF was comparable with Filgrastim and weaker than PEG-Filgrastim treated rats. In vitro and in vivo results suggested the ABD fusion as a potential approach for improving GCSF properties.

scholarly journals Antimicrobial Peptides from Human Platelets

2002 ◽  
Vol 70 (12) ◽  
pp. 6524-6533 ◽  
Author(s):  
Yi-Quan Tang ◽  
Michael R. Yeaman ◽  
Michael E. Selsted
Keyword(s):  
Antimicrobial Peptides ◽  
High Performance ◽  
Antimicrobial Activities ◽  
Reversed Phase ◽  
Human Platelets ◽  
Platelet Factor ◽  
E Coli ◽  
Mediators Of Inflammation ◽  
Human Thrombin

ABSTRACT Platelets share structural and functional similarities with granulocytes known to participate in antimicrobial host defense. To evaluate the potential antimicrobial activities of platelet proteins, normal human platelets were stimulated with human thrombin in vitro. Components of the stimulated-platelet supernatants were purified to homogeneity by reversed-phase high-performance liquid chromatography. Purified peptides with inhibitory activity against Escherichia coli ML35 in an agar diffusion antimicrobial assay were characterized by mass spectrometry, amino acid analysis, and sequence determination. These analyses enabled the identification of seven thrombin-releasable antimicrobial peptides from human platelets: platelet factor 4 (PF-4), RANTES, connective tissue activating peptide 3 (CTAP-3), platelet basic protein, thymosin β-4 (Tβ-4), fibrinopeptide B (FP-B), and fibrinopeptide A (FP-A). With the exception of FP-A and FP-B, all peptides were also purified from acid extracts of nonstimulated platelets. The in vitro antimicrobial activities of the seven released peptides were further tested against bacteria (E. coli and Staphylococcus aureus) and fungi (Candida albicans and Cryptococcus neoformans). Each peptide exerted activity against at least two organisms. Generally, the peptides were more potent against bacteria than fungi, activity was greater at acidic pHs, and antimicrobial activities were dose dependent. Exceptions to these observations were observed with PF-4, which displayed a bimodal dose-response relationship in microbicidal assays, and Tβ-4, which had greater activity at alkaline pHs. At concentrations at which they were individually sublethal, PF-4 and CTAP-3 exerted synergistic microbicidal activity against E. coli. Collectively, these findings suggest a direct antimicrobial role for platelets as they are activated to release peptides in response to trauma or mediators of inflammation.

scholarly journals Physical exercise increases urinary excretion of lipoxin A4 and related compounds

2003 ◽  
Vol 94 (6) ◽  
pp. 2237-2240 ◽  
Author(s):  
Sebastiano Gangemi ◽  
Graziella Luciotti ◽  
Etrusca D'Urbano ◽  
Agostino Mallamace ◽  
Domenico Santoro ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
High Performance ◽  
Reversed Phase ◽  
Strenuous Exercise ◽  
Lipoxin A4 ◽  
Safeguard Mechanism ◽  
First Time ◽  
Related Compounds

Lipoxins (LX) are lipoxygenase-derived eicosanoids with potent anti-inflammatory activities and vascular bed-dependent vasodilatory actions. LX can be formed in vitro and in vivo in a number of conditions, and we have reported that immunoreactive LXA4 (iLXA4) is physiologically excreted with human urine. Using a recently developed LX extraction method coupled to an ELISA, we examined whether iLXA4 excretion was modified by strenuous exercise, which is known to trigger potential LX-forming events. Maximal exertion significantly increased iLXA4 urinary excretion in nine healthy volunteers (0.061 ± 0.023 vs. 0.113 ± 0.057 ng/mg creatinine; P = 0.028). iLXA4 levels returned to baseline after 6 h and increased, although at a smaller extent, after 24 h. A significant correlation ( r = 0.988) was denoted between iLXA4 ELISA measurements and reversed-phase high-performance liquid chromatography quantitation of a previously described urinary tetraene, confirming its LXA4-related nature. These findings show for the first time that an increase in excretion of LXA4-related compounds can be observed in response to strenuous exercise. This may be the reflection of an enhanced LX biosynthesis, which may represent a safeguard mechanism that keeps the inflammatory reaction triggered by physical stress under control.

scholarly journals In Vitro and In Vivo Evaluation of Two Hydroxychloroquine Tablet Formulations: HPLC Assay Development

2020 ◽  
Vol 59 (1) ◽  
pp. 71-78
Author(s):  
Jaber Emami ◽  
Moloud Kazemi ◽  
Anahita Salehi
Keyword(s):  
High Performance ◽  
Internal Standard ◽  
Reversed Phase ◽  
Hplc Method ◽  
In Vivo Studies ◽  
Crossover Fashion ◽  
Content Uniformity ◽  
In Vivo Evaluation

Abstract The relative in vitro and in vivo evaluation of two hydroxychloroquine (HCQ) products was conducted. In vitro studies involved assay, content uniformity and dissolution test, and a two-way crossover fashion were used for in vivo studies. Blood samples were collected at appropriate intervals and HCQ levels were measured using a validated reversed-phase high-performance liquid chromatography (HPLC) method. The drug and the internal standard, chloroquine (CQ), were extracted from blood with diethyl ether, separated and dried under nitrogen gas. Residues were reconstituted in the mobile phase and analyzed at 340 nm on a μ-bondapack C18 (250 × 4.6 mm) HPLC column with acetonitrile:methanol:KH2PO4 (10:10:80) mixture containing 0.01% triethylamine. The standard curve was linear within 50–1,500 ng/mL HCQ (R2 = 0.9996), relative errors were 1.6 to 5%, and the CV% ranged from 7 to 15.4. The resolution factor and RSD were 1.62 and 0.35% and in vitro data of both products met the USP requirements. The 90% confidence intervals for the ratios of the AUC0–96, Cmax and Tmax and their corresponding logarithmically transformed values of generic product over those of Plaquenil® were within the acceptable limit of 0.80–1.20 and 0.80–1.25, respectively. Therefore, the generic HCQ was bioequivalent to the innovator formulation.

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