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Surfactant protein D is a divalent cation-dependent carbohydrate-binding protein.
- Source :
-
The Journal of biological chemistry [J Biol Chem] 1990 Apr 05; Vol. 265 (10), pp. 5755-60. - Publication Year :
- 1990
-
Abstract
- Surfactant protein D (SP-D, CP4) is a collagenous surfactant-associated glycoprotein synthesized by lung type II epithelial cells. SP-D can be selectively and efficiently eluted from isolated rat surfactant with glucose, maltose, and certain other saccharides. We therefore examined the ability of the purified protein to interact with carbohydrates in vitro. Saccharide-substituted bovine serum albumins (BSA neoglycoproteins) were adsorbed to plastic wells, and binding of purified SP-D was quantified with monospecific antibodies to SP-D using an indirect immunoassay. SP-D showed specific calcium-dependent binding to alpha-D-glucosidophenyl isothiocyanate-BSA and maltosyl-BSA, but negligible binding to beta-D-glucosidophenyl isothiocyanate-BSA or unconjugated BSA. The most efficient inhibitors of SP-D binding were alpha-glucosyl-containing saccharides (e.g. isomaltose, maltose, malotriose). SP-D showed quantitative binding to maltosyl-agarose and was specifically eluted with maltose or EDTA. High affinity binding to maltosyl-BSA was also demonstrated using a solution-phase polyethylene glycol precipitation assay. These studies demonstrate that SP-D is a calcium dependent lectin-like protein and that the association of SP-D with surfactant is mediated by carbohydrate-dependent interactions with specificity for alpha-glucosyl residues.
- Subjects :
- Animals
Binding, Competitive
Calcium pharmacology
Cations, Divalent
Cells, Cultured
Edetic Acid pharmacology
Glucose analogs & derivatives
Glucose metabolism
Immunoassay
Isomaltose pharmacology
Lung metabolism
Maltose metabolism
Maltose pharmacology
Pulmonary Surfactant-Associated Protein D
Pulmonary Surfactants analysis
Rats
Serum Albumin, Bovine metabolism
Trisaccharides pharmacology
Bronchoalveolar Lavage Fluid analysis
Carrier Proteins metabolism
Glycoproteins metabolism
Pulmonary Surfactants metabolism
Receptors, Cell Surface
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9258
- Volume :
- 265
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- The Journal of biological chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 2108147