Distinct glycosylation in interstitial and serum tenascin-X

Abstract

We developed an easy and fast method to isolate extracellular matrix tenascin-X (TNX) from various tissues in mice based on TNX antibody affinity purification. We purified approximately 350-kDa cellular interstitial TNX (iTNX) from the spleen, liver and kidney as well as 200-kDa serum TNX (sTNX). Since the nature and significance of glycosylation in TNX remains to be elucidated, glycobiochemical properties of purified TNX were characterized by lectin blot analysis. Lectin blots by Con A, LCA, PHA-E4, RCA120 or WGA revealed the presence of N-glycan in the cellular TNX and especially complex-type N-glycan in the serum TNX. In addition, the iTNX from liver and kidney also possessed O-glycan based on the reaction to PNA. The binding to AAL indicated that iTNX from the three tissues possesses fucose linked α1,6 to a pentasaccharide core, whereas sTNX does not. The reaction to SSA but not to MAM suggested the presence of sialic acid linked α2,6 to galactose in both cellular and serum TNX. Lectin blots of trypsin-treated iTNX from the spleen also demonstrated that WGA alone reacts to the t300 product derived from the amino-terminal 300-kDa portion. © 2007 Pharmaceutical Society of Japan.