Apr 20th, 1:00 PM - 4:00 PM
LC/ESI-MS Identification of Tyrosine O-Sulfation Sites Within Col 11a1 Protein Isoforms
Sulfation is among the most common post translational modifications to eukaryotic proteins. It has functional implications in a wide variety of biological processes including inflammation, clotting, and angiogenesis through facilitation of protein-protein interactions. A number of extracellular matrix(ECM) proteins are sulfated yet the functional significance of sulfation in the ECM is not known. Mass spectrometry is a robust and widely used platform for determining the location of post translational modifications, however the labile nature of sulfation makes it difficult to detect directly. Specific sites can be determined using a subtractive approach in which unmodified tyrosines are blocked using a treatment of sulfosuccinimidal acetate (S-NHSAc). Detection of non-S-NSHAc modified tyrosines by tandem LC/ESI MS reveals potential native sites of sulfation. Collagen (XI) is an ECM protein whose α1 chain isoforms regulate collagen fibril diameter through protein-protein interactions. Determination of tyrosine sulfation sites on Collagen (XI) is a preliminary step in characterization of the functional implications of sulfation on ECM protein-protein interactions, and by extension ECM organization.