Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Phase II Reactions: Methylation Reactions01:17

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 Modifications in the RER01:26

Protein Modifications in the RER

Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal sequences.
Sulfur Assimilation01:20

Sulfur Assimilation

Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to become...
Phase II Reactions: Acetylation Reactions01:24

Phase II Reactions: Acetylation Reactions

Acetylation, a phase II biotransformation reaction, introduces an acetyl group to drugs or their metabolites. Acetyltransferase enzymes facilitate this reaction, which resembles α-amino acid conjugation due to the addition of a functional group to the drug molecule.
The substrates for acetylation are typically drugs or their metabolites with an amino, sulfonamide, or hydrazine functional group. Acetylation can occur at several points in the drug molecule, including primary, secondary, and...
Transfer RNA Synthesis02:36

Transfer RNA Synthesis

One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...

You might also read

Related Articles

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

Sort by
Same author

Sustainable steps forward in vitamin B<sub>12</sub>-catalysis.

Chemical communications (Cambridge, England)·2026
Same author

Addition to "Redirecting Formate Delivery toward Alkenes: Markovnikov α-Carboxylation via Cobalt/Photoredox/Brønsted Acid Catalysis".

Journal of the American Chemical Society·2026
Same author

Monitoring the Switching from Base-on to Base-off Forms of Vitamin B<sub>12</sub> by Natural and Magnetic Circular Dichroism Spectroscopies.

Analytical chemistry·2026
Same author

Zincke-Imine-Based Peripheral Editing of 2-Arylpyridines to Access 3-Acylpyridines.

Organic letters·2025
Same author

Redirecting Formate Delivery toward Alkenes: Markovnikov α-Carboxylation via Cobalt/Photoredox/Bro̷nsted Acid Catalysis.

Journal of the American Chemical Society·2025
Same author

Red-Light-Induced Cysteine Modifications Suitable for Protein Labeling.

ACS organic & inorganic Au·2025

Related Experiment Video

Updated: May 11, 2026

Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins
13:59

Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins

Published on: December 12, 2013

Vitamin B12: chemical modifications.

Keith o óProinsias1, Maciej Giedyk, Dorota Gryko

  • 1Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.

Chemical Society Reviews
|May 30, 2013
PubMed
Summary

Vitamin B12 is crucial for mammalian metabolism. This review details advancements in synthesizing, analyzing, and purifying vitamin B12 (cobalamin) derivatives, offering insights into its chemistry.

Area of Science:

  • Biochemistry
  • Organic Chemistry
  • Mammalian Metabolism

Background:

  • Vitamin B12 (cobalamin) is essential for numerous metabolic processes in mammals.
  • Extensive research has focused on its biological role, stimulating interest in its chemical properties.

Purpose of the Study:

  • To summarize recent advancements in vitamin B12 chemistry.
  • To provide a deeper understanding of cobalamin synthesis, analysis, and purification.

Main Methods:

  • Review of novel synthetic methodologies for cobalamin derivatives.
  • Analysis of new techniques for studying cobalamin structure and function.
  • Exploration of creative purification strategies for vitamin B12 compounds.

Main Results:

More Related Videos

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
12:07

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration
12:03

Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration

Published on: January 22, 2014

Related Experiment Videos

Last Updated: May 11, 2026

Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins
13:59

Methods to Identify the NMR Resonances of the 13C-Dimethyl N-terminal Amine on Reductively Methylated Proteins

Published on: December 12, 2013

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
12:07

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration
12:03

Expression, Isolation, and Purification of Soluble and Insoluble Biotinylated Proteins for Nerve Tissue Regeneration

Published on: January 22, 2014

  • Development of diverse new methods for synthesizing and analyzing cobalamin derivatives.
  • Establishment of innovative purification techniques for vitamin B12.
  • Comprehensive overview of the current state of vitamin B12 chemistry.

Conclusions:

  • Significant progress has been made in the chemical manipulation and understanding of vitamin B12.
  • This review consolidates key findings, facilitating further research in cobalamin chemistry.