Study of cysteine residues

Get insight on the cysteines residues of one of many proteins using cystein-tarageted chemistry and mass spectrometry.

Graphical representation of a disulfide bond

How to study cysteine residues by mass spectrometry

Cysteine is an amino acid that is very interesting from a biological point of view. Their thiol side chain is indeed implicated in many enzymatic reactions and can form disulfide bridge with another cysteine residue in the same protein or in another one. Therefore, the study of cysteine can bring a lot of light in many areas of fundamental and applied research.

There are many available tools and strategies to study cysteine using mass spectrometry. In the majority of the cases, the workflow will involve the addition of a chemical group using thiol-targeted chemistries to the cysteine. Conversely, some experiments require that the disulfide bridges be kept intact. For example, we can digest a protein without prior reduction and alkylation. This will result in a mixture of peptides that are still bound to one another by disulfide bridges, which we can identify using mass spectrometry. 

Available workflows

Since listing every possible workflow would be near impossible, here are some examples of available solutions to study cysteine using mass spectrometry. We can adapt the study design to your needs using different combinations of protocols and workflow to. Please use the form to communicate with our experts and see how we can help you!

  • Differential alkylation (compare free cysteine in two conditions)
  • Disulfide bridge mapping (using native dipeptides)
  • Targeted quantification
  • Comparative proteomics
  • Intact protein analyses

Data reports

Data reports for cysteine-targeted workflows are tailored to your needs. We will provide a spreadsheet with all the information you need to understand the results. We always provide both analyzed and raw data and are absolutely transparent about how the data has been treated. This way, you can use the results safely and publish undoubtedly.

Contact us to design your study on cysteine residues

My personal experience of collaborating with PhenoSwitch Bioscience was really amazing and great. Ribosomal protein paralogs have very limited number of amino acid differences. If it were not for PhenoSwitch, it would not have been possible to get such a high quality identification and quantification of duplicated ribosomal proteins in yeast. I am highly indebted and thankful for their perseverance, commitment, help and guidance during the tough times of optimization. If you you need to use MS for identification and quantification of your molecules, I strongly recommend you to talk to these guys!
Mustafa Malik Ghulam, Post Doctoral Fellow, RNA Therapeutic Institute, Umass Medical School, Worcester, Massachussetts

"PhenoSwitch Bioscience Inc has provided us with outstanding efficacious service, high quality data and exemplary data analysis over the past three years."

Stephen Naylor, Ph.D., CEO at ReNeuroGen LCC, Milwaukee, USA
"They have provided excellent data in a timely manner on a number of metabolism and protein studies ongoing in my group"
Klaus Klarskov, Ph.D., Professor at Université de Sherbrooke, Canada
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