Glycosylation of Natural Human Neutrophil Gelatinase B and Neutrophil Gelatinase B-Associated Lipocalin†

Pauline M. Rudd, Taj S. Mattu, Stefan Masure, Tomas Bratt, Philippe E. Van den Steen, Mark R. Wormald, Bernard Küster, David J. Harvey, Niels Borregaard, Jo Van Damme, Raymond A. Dwek, Ghislain Opdenakker
1999 Biochemistry  
Gelatinase B is a matrix metalloproteinase (MMP-9) involved in tissue remodeling, development, cancer, and inflammation. Neutrophils produce three major forms of (pro)gelatinase B: 92 kDa monomers, homodimers, and complexes of gelatinase B covalently bound to neutrophil gelatinase B-associated lipocalin (NGAL). In contrast to the case for other proteinases, little information about the glycosylation of any natural human MMP is available. Here, both gelatinase B and NGAL were purified from human
more » ... peripheral blood neutrophils, and the entire contents of the released N-and O-glycan pools were analyzed simultaneously using recently developed high-performance liquid chromatography-based technology. The results are discussed within the context of the domain structure of gelatinase B and a molecular model of NGAL based on data from this study and the three-dimensional nuclear magnetic resonance (NMR) structure of the protein. More than 95% of the N-linked glycans attached to both gelatinase B and NGAL were partially sialylated, core-fucosylated biantennary structures with and without outer arm fucose. The O-linked glycans, which were estimated to comprise approximately 85% of the total sugars on gelatinase B, mainly consisted of type 2 cores with Gal 1,4GlcNAc (lactosamine) extensions, with or without sialic acid or outer arm fucose. This paper also contains the first report of O-linked glycans attached to NGAL. Although both proteins were isolated from neutrophils and contained O-linked glycans mainly with type 2 cores, the glycans attached to individual serine/threonine residue(s) in NGAL were significantly smaller than those on gelatinase B. In contrast to NGAL, gelatinase B contains a region rich in Ser, Thr, and Pro typical of O-glycosylated mucin-like domains. Remodeling of the extracellular matrix (ECM) 1 is achieved by both de novo synthesis and enzymatic modifications of ECM components. The matrix metalloproteinases (MMPs) (collagenases, stromelysins, matrilysins, gelatinases, and membrane-type metalloproteinases) are a family of enzymes which control this process (1, 2). Among these, gelatinase B (MMP-9, EC is the most complex in terms of protein domain structure. The regulation of expression and activity of gelatinase B is also more complex than those of most other MMPs. For instance, in contrast to gelatinase A, gelatinase B is not produced constitutively by most cells, but its activity is induced by different stimuli depending on the cell type, thus providing a means of raising the local concentration of gelatinolytic activity in response to specific †
doi:10.1021/bi991162e pmid:10529240 fatcat:ljheblgp7zagzox4mck3fb6j2a