Use of lectin probes on tissues and sympathetic saliva to study the glycoproteins secreted by rat submandibular glands.

Abstract

We used a panel of nine lectins to detect the glycosylation patterns of rat submandibular glycoproteins. Binding of lectins was assessed on tissue sections and on Western blots of electrophoretically separated glycoproteins from glandular extracts or sympathetic saliva. Histochemical staining of tissue sections showed that two lectins (DBA and SBA) with affinity for terminal GalNAc residues were localized specifically to acinar cells. In contrast, LTA and UEA-I (alpha Fuc-directed) and LFA (NeuAc-directed) bound exclusively to granular tubule cells. PNA and MPA (beta Gal-directed), LCA (alpha Man- and alpha Glc-directed), WGA (beta GlcNAc- and NeuAc-directed), and sWGA (beta GlcNAc-directed) bound to both acinar and granular tubule cells. On electroblot preparations, LFA, PNA, WGA, DBA, and SBA reacted with high molecular weight acinar mucin components both in glandular extracts and in saliva. LTA, UEA-I, LFA, PNA, MPA, LCA, WGA, sWGA, and DBA bound to lower molecular weight bands on blots known to contain granular tubular proteinases. Lectin binding to acini and granular tubules was reduced in sections and in most bands from glandular extracts after sympathetic nerve stimulation. Our results show that (a) secretory glycoproteins from rat submandibular acinar cells are non-fucosylated and contain abundant alpha GalNAc and NeuAc and a small proportion of beta Gal in their oligosaccharide side chains, and (b) alpha Fuc, NeuAc, beta Gal, and alpha GalNAc form the major carbohydrate moieties of the secretory glycoproteins from granular tubules. The results confirm the considerable potential of lectin probes for studying glycoproteins in secretions and in their cells of origin.

Histological and histochemical analysis of the gastrointestinal tract of the common pipistrelle bat (Pipistrellus pipistrellus)

“…For saliva of Rattus norvegicus similar binding patterns can be found. 58 Salivary mucins act as a protective gel of the mucosa and as a lubricant in the esophageal lumen. 59 …”

Characterization of the Human Submandibular/Sublingual Saliva Glycoproteome Using Lectin Affinity Chromatography Coupled to Multidimensional Protein Identification Technology

“…In the oral cavity, well characterized, abundant salivary glycoproteins constitute a major part of the salivary proteome with biological and physiological functions, e.g. lubrication, protection, agglutination, digestion, defense, and antibacterial 13,22,23,28,35,53,60,71,79 .…”

“…Lectins recognize specific carbohydrate motifs, binding is reversible, multiple glycan-binding sites are available, and glycans can be recovered for future characterization, while quantification and chemical derivatization are avoided 15–18,28,34,35,48,51,58,83 . In addition, lectin-based methodologies have been used for diagnosing pathological sates, investigating mutants of model organisms, identifying protein polymorphisms, blood group typing, bacteria typing, saliva-induced aggregation assays of oral bacteria, histochemistry, and quality control analysis of recombinant glycoprotein pharmaceuticals 26,39,48,55,79,83–85 . Consequently, we reported here a combined approach based on lectin-affinity chromatography and MudPIT mass spectrometry to generate an in-depth profile of the SM/SL glycoproteome.…”

“…17, 27,59,70,76,77 In the oral cavity, well-characterized, abundant salivary glycoproteins constitute a major part of the salivary proteome with biological and physiological functions, for example, lubrication, protection, agglutination, digestion, defense, and antibacterial. 13,22,23,28,35,53,60,71,79 It is well recognized that alterations in glycosylation are reflected in a variety of pathologies. 16,18,21,25,27,34,35,47,54,58,59,80 Therefore, it is crucial to do a comprehensive and robust glycoproteomic profiling.…”

Lectins and antibodies against blood-group antigens as tools for studying the cellular source of glycoproteins in human bronchial fluid: a comparison of morphological and biochemical observations

“…The binding patterns of selected lectins and antibodies against blood group antigens of the ABO system have been compared in histochemical sections with the results of Western-blot preparations of bronchial secretions. This approach appears to be promising, since morphological and biochemical methods have recently been applied to the analysis of glycoprotein secretions in other organs (e.g., Zhang et al 1994). Some of this work has previously been presented at the European Respiratory Society (Bals et al 1991;Bals and Welsch 1992).…”