Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

RNA Stability

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...

Bioactivation and Tissue Toxicity

Bioactivation and Tissue Toxicity

Bioactivation is a metabolic process that transforms less reactive substances into highly reactive metabolites, initiating tissue toxicity. This transformation can lead to various toxic effects, including carcinogenesis and teratogenesis. Reactive metabolites are classified into two main types: electrophiles and free radicals.Electrophiles are electron-deficient species and are produced primarily by the enzyme cytochrome P-450 during the metabolism of compounds containing carbon, nitrogen, or...

Phase II Reactions: Methylation Reactions

Phase II Reactions: Methylation Reactions

Methylation is a phase II biotransformation process involving the attachment of a methyl group to a substrate. Enzymes known as methyltransferases orchestrate this reaction.
The mechanism of methylation unfolds in two stages. The first stage sees a methyltransferase enzyme facilitating the transfer of a methyl group from S-adenosylmethionine (SAM) to the substrate, forming S-adenosylhomocysteine (SAH). The second stage involves further metabolism of SAH into homocysteine, which can be recycled...

Protein Denaturation

Protein Denaturation

The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. Folding of the polypeptide chain takes place under specific conditions that energetically favor the folded conformation. In contrast, protein denaturation occurs spontaneously under unfavorable conditions that disrupt the integrity of the folded conformation. Thus, the chemical and physical environment of a protein, such as significant changes in pH...

Epigenetic Regulation

Epigenetic Regulation

Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...

Epigenetic Regulation

Epigenetic Regulation

Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Ester hydrolysis of polysorbate 80 in mAb drug product: evidence in support of the hypothesized risk after the observation of visible particulate in mAb formulations.

Journal of pharmaceutical sciences·2014

Same author

Probing the solution structure of tumor necrosis factor-α homotrimer and heterotrimer after complex perturbation using electrospray ionization mass spectrometry.

Journal of molecular recognition : JMR·2012

Same author

Discovery and mechanism of ustekinumab: a human monoclonal antibody targeting interleukin-12 and interleukin-23 for treatment of immune-mediated disorders.

mAbs·2011

Same author

Structural basis for the dual recognition of IL-12 and IL-23 by ustekinumab.

Journal of molecular biology·2010

Same author

Recognition and identification of UV-absorbing leachables in EPREX pre-filled syringes: an unexpected occurrence at a formulation-component interface.

PDA journal of pharmaceutical science and technology·2008

Same author

RecA dimers serve as a functional unit for assembly of active nucleoprotein filaments.

Biochemistry·2006

Search research articles

Related Experiment Video

Updated: Jul 3, 2026

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation

Published on: June 21, 2021

The oxidation of methionine-54 of epoetinum alfa does not affect molecular structure or stability, but does decrease

Steven R Labrenz¹, Melissa A Calmann, George A Heavner

¹Pharmaceutical Technology, Global Biologics Supply Chain, LLC, 200 Great Valley Parkway, Malvern, PA 19355, USA. slabrenz@cntus.jnj.com

PDA Journal of Pharmaceutical Science and Technology

|July 30, 2008

Summary

Oxidation of methionine-54 in epoetinum alfa does not alter its structure or stability. However, increased methionine sulfoxide levels reduce biological activity, impacting potency at high concentrations.

More Related Videos

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein

Published on: October 12, 2017

Exploring the Arginine Methylome by Nuclear Magnetic Resonance Spectroscopy

Exploring the Arginine Methylome by Nuclear Magnetic Resonance Spectroscopy

Published on: December 16, 2021

Related Experiment Videos

Last Updated: Jul 3, 2026

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation

Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation

Published on: June 21, 2021

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein

Cell-free Biochemical Fluorometric Enzymatic Assay for High-throughput Measurement of Lipid Peroxidation in High Density Lipoprotein

Published on: October 12, 2017

Exploring the Arginine Methylome by Nuclear Magnetic Resonance Spectroscopy

Exploring the Arginine Methylome by Nuclear Magnetic Resonance Spectroscopy

Published on: December 16, 2021

Area of Science:

Biochemistry
Protein Chemistry
Pharmacology

Background:

Erythropoietin (EPO) therapy, including EPREX (epoetinum alfa), treats anemia in renal failure and chemotherapy patients.
The impact of methionine-54 oxidation on EPO structure, stability, and activity was previously unevaluated.

Purpose of the Study:

To investigate the structural and functional consequences of methionine-54 oxidation in recombinant human erythropoietin (rhEPO).
To determine if methionine oxidation affects the stability and biological activity of epoetinum alfa.

Main Methods:

Chemical oxidation of methionine-54 using tert-Butylhydroperoxide and hydrogen peroxide.
Fluorescence spectroscopy, circular dichroism, and thermal unfolding studies to assess structural changes.
Biological activity assays to evaluate functional impact.

Main Results:

Methionine-54 oxidation caused a blue shift in fluorescence, indicating local environmental changes near tryptophan-51.
No alterations in the folded structure or global thermodynamic stability (Tm = 49.5°C) were observed.
Biological activity decreased proportionally to the level of methionine sulfoxide, suggesting an allosteric effect.

Conclusions:

Methionine oxidation does not affect the overall structure or stability of rhEPO.
Oxidation impacts rhEPO potency, but only at levels substantially higher than typically found in EPREX.
These findings provide insights into the stability and activity profile of therapeutic erythropoietins.