Related Experiment Video
Updated: Aug 7, 2026

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
Published on: October 4, 2017
Analysis of sequence requirements for protein tyrosine sulfation
1Department of Animal Physiology, University of California, Davis 95616.
Abstract:
We analyzed sequences surrounding known tyrosine sulfation sites to determine the characteristics that distinguish these sites from those that do not undergo sulfation. Tests evaluated the number and position of acidic, basic, hydrophobic, and small amino acids, as well as disulfide and N-glycosylation (sugar) sites. We determined that composition-based tests that select close to 100% of known tyrosine sulfation sites reject 97% of the non-sulfated tyrosines. The acidic test, by far the most selective, eliminated 95% of the non-sulfated tyrosine residues and none of the sulfated tyrosines. Including the basic, hydrophobic, and disulfide tests increased the elimination rate to 97%. Whereas no position flanking the tyrosine residues had the same amino acid always present, imperfectly conserved amino acids found in some positions will improve the specificity of the tests.
Related Concept Videos
Protein and Protein Structure
A protein's shape is critical to its function. For example, an enzyme can...
Signal Sequences and Sorting Receptors
Tail-anchoring of Proteins in the ER Membrane
Protein Modifications in the RER
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.
Protein Folding Quality Check in the RER
Amino Acid Biosynthetic Pathways

