1. Identity of human extra parotid glycoprotein (EP-GP) with secretory actin binding protein (SABP) and its biological properties.
- Author
-
Schenkels LC, Schaller J, Walgreen-Weterings E, Schadee-Eestermans IL, Veerman EC, and Nieuw Amerongen AV
- Subjects
- Amino Acid Sequence, Apolipoproteins D, Carbohydrates analysis, Carrier Proteins isolation & purification, Carrier Proteins metabolism, Cell Wall metabolism, Cell Wall ultrastructure, Glycoproteins isolation & purification, Glycoproteins metabolism, Humans, Immunoblotting, Kinetics, Male, Microscopy, Electron, Molecular Sequence Data, Molecular Weight, Organ Specificity, Salivary Proteins and Peptides isolation & purification, Salivary Proteins and Peptides metabolism, Semen, Seminal Vesicles, Sequence Homology, Amino Acid, Streptococcus ultrastructure, Submandibular Gland, Apolipoproteins, Carrier Proteins chemistry, Glycoproteins chemistry, Membrane Transport Proteins, Microfilament Proteins metabolism, Salivary Proteins and Peptides chemistry, Streptococcus metabolism
- Abstract
In this paper the identity of the salivary protein EP-GP (extra-parotid glycoprotein) is reported, also apparent in other human secretions. Immunochemical and biochemical analysis demonstrated that EP-GP is similar to the secretory actin-binding protein (SABP), also known as gross cystic disease fluid protein-15 (GCDFP-15) and prolactin-inducible protein (PIP). The molecular mass and charge microheterogeneity of EP-GP, also observed for SABP, was shown to be predominantly caused by the carbohydrate moiety. In addition, evidence was given that EP-GP is not related to the lipocalin Von Ebner's gland protein (human; VEGh). The biological significance of EP-GP and its homologues is not clear. EP-GP bound to actin and fibrinogen as described for SABP and GCDFP-15. However, the affinity for these proteins does not appear to have any direct physiological role in the mucosal secretions. On the other hand, EP-GP binds to several bacteria. By electron microscopy the ultrastructural localization is demonstrated of EP-GP to the cell wall of both Streptococcus salivarius HB and its cell appendage-lacking mutant Streptococcus salivarius HB-C12. Concerning this finding we hypothesize on the possible functional aspects of this enigmatic protein EP-GP.
- Published
- 1994
- Full Text
- View/download PDF