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 posttranslational modifications to eukaryotic proteins. It has functional implications in a wide variety of biological processes including inflammation, clotting, and angiogenesis through facilitation of proteinprotein 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 posttranslational 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.