Modification specific antibodies

Post-translation modifications play a significant role in protein structure and function. More of 200 post-translational modifications exist in vivo and each of them plays an important role. At ProteoGenix, we develop anti-PTM antibodies for various research applications: cell signaling, disease diagnostics, protein structure and function, development of therapeutic proteins…

Glycosylation is one of the most frequent but also complex and most misunderstood post-translational modifications. It is commonly observed in secreted and membrane protein.  Oligosaccharides can be either N-linked to a nitrogen atom (usually to the amide nitrogen of an asparagine residue) or O-linked to an oxygen atom of a serine or threonine.
Glycosylation is also particularly important in therapeutics as most of the approved biotherapeutics are glycoproteins. It has been shown to influence various parameters such as protein folding, protein targeting, stability, half-life, immunogenicity… Thus, the detection of glycosylated targets (and the development of highly specific and sensitive glycosylation-specific antibodies) with great precision is a key point in the development of new biopharmaceuticals and for many other research applications.

Looking for a glycosylation-specific antibody? Send us your requirements!

Protein phosphorylation corresponds to the attachment of a phosphate moiety to an amino-acid residue, usually a serine (in most of the cases), a threonine or a tyrosine. The phosphorylation step is done by kinases whereas the dephosphorylation step is performed by phosphatases. Phosphorylation is involved in the regulation of many cellular processes such as cell growth, cell apoptosis, cell signaling…

Need a phosphorylation-specific antibody for your experiments? We make it for you!

Protein methylation refers to the addition of a methyl group to an amino acid residue. This methyl addition, mediated by methyltransferases, can occur either on a nitrogen atom (N-methylation) or on an oxygen atom (O-methylation). Due to its small size, methylation does not drastically impact the sterical hindrance of the modified residue. Methylation is known to increase protein hydrophobicity and to neutralize a negative charge when bound to carboxylic acids. It has been found to occur on up to 8 different amino acids in various organisms but the most commonly studied methylated residues remain lysines and arginines. Methylation of lysine and arginine at histones is known to play an important role in the regulation of epigenetics and diseases.

Looking for a methylation specific antibody? Contact us and talk together about your project!

Protein ubiquitination refers to the addition of an 8kDA polypeptide consisting of 76 AA to the N-terminus of a protein. Ubiquitination represents a multi-enzymatic process involving the successive action of three enzymes: ubiquitin-activating enzyme E1, ubiquitin-conjugating enzyme E2 and ubiquitin ligase E3. Ubiquitination can occur in two different manner:

• Monoubiquitination which correspond to the addition of one ubiquitin molecule and is involved in endocytic traffic regulation, inflammation and DNA repair

• Polyubiquitination resulting in the formation of a polyubiquitinated protein recognized by the 26S proteasome in the protein degradation pathway.

Need to develop your custom ubiquitination-specific antibody? Contact our account managers!

N-acetylation can be a reversible or irreversible process and consists in the transfer of an acetyl group to a nitrogen atom. N-acetylation occurs in two steps:

1. The cleavage of methionine by methionine aminopeptidase

2. The addition of an acetyl group from acetyl-CoA by N-acetyltransferase.

Most of the eukaryotic proteins are acetylated however the biological significance is still unclear.

Acetylation is very well studied in the case of histone proteins where lysine acetylation it occurs via histone acetyltransferase (HAT) and results in increased transcriptional activity.

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Amidation corresponds to the replacement of a protein’s C-terminal carboxyl group with an amide group. It is one of the most common C-terminal PTM.
Protein amidation is catalyzed by a bifunctional enzyme, peptidylglycine alpha-amidating monooxygenase (PAM). PAM corresponds to a precursor which contains 2 enzymes catalyzing the alpha-amidation reaction:

• Peptidylglycine alpha-hydroxylating monooxygenase (PHM) catalyses the stereospecific  hydroxylation of the glycine alpha-carbon of all the peptidylglycine substrates

• Peptidyl-alpha-hydroxyglycine alpha-amidating lyase (PAL) generates the alpha-amidated product.

The amidation rule isn’t fully understood yet. However, following some studies on the interaction of amidated peptides with their respective receptors, it is thought to play a determinant role in the ligand-receptor interaction. Amidation neutralizes the peptide’s C-terminus negative charge and, thus increases its hydrophobicity and potentially its ability to bind to a receptor.

You need a custom modification specific antibody for your experiments? Contact our PhD account managers who will be happy to design your personalized solution.