The uptake of serum albumin by maturation-stage rodent enamel and the resulting effects on the growth of enamel crystallites were investigated in vitro. Albumin uptake was demonstrated by means of gel electrophoresis and confirmed by Western blotting with use of monoclonal antibodies. Measurement of crystal size was carried out by direct TEM measurement of enamel crystallite outlines after incubations in metastable solutions of calcium phosphate. The ability of endogenous enamel enzymes to degrade albumin was investigated by substrate-specific zymography. The results showed that albumin could be taken up by maturation-stage enamel and produce inhibition of crystallite growth. There was no detectable proteolytic activity in the enamel against albumin substrate, which suggests that albumin entering enamel by extravasation in vivo may produce incomplete tissue maturation, resulting in a white, opaque appearance on eruption.
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References
1.
Bachra BN, Fischer Hra (1968). Mineral deposition in collagen in vitro. Calcif Tissue Res2:343-352.
2.
Banda MJ, Werb Z., McKerrow J. (1987). Elastin degradation. In: Cunningham LW, editor. Methods in enzymology. New York (NY): Academic Press, 288-305.
3.
Couwenhoven RI, Davis C., Snead ML (1989). Mouse ameloblasts do not transcribe the albumin gene. Calcif Tissue Int45:367-371.
4.
DenBesten PK, Heffernan LM (1989). Separation by polyacrylamide gel electrophoresis of multiple proteases in rat and bovine enamel. Arch Oral Biol34:399-404.
5.
Doi Y., Eanes ED, Shimokawa H., Termine JD (1984). Inhibition of seeded growth of enamel apatite crystals by amelogenin and enamelin proteins in vitro. J Dent Res63:98-105.
6.
Fejerskov 0, Thylstrup A., Larsen MJ (1977). Clinical and structural features and possible pathogenic mechanism of dental fluorosis. Scand J Dent Res85:510-534.
7.
Garant PR, Gillespie R. (1969). Capillaries in the papillary layer of the enamel organ. Anat Rec163:71-80.
8.
Herold RC, Rosenbloom J. (1990). Immunocytochemical localization of enamelin proteins in developing bovine teeth. Arch Oral Biol35 :373-379.
9.
Hiller CR, Robinson C., Weatherell JA (1975). Variations in the composition of developing rat incisor enamel. Calcif Tissue Int18:1-12.
10.
Hlady V., Furedi-Milhofer H. (1979). Adsorption of human serum albumin on precipitated hydroxyapatite. J Colloid Interface Sci69:460-468.
Laemmli UK (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature227:680-684.
13.
Limeback H., Sakarya H., Chu W., MacKinnon M. (1989). Serum albumin and its acid hydrolysis peptides dominate preparations of mineral-bound enamel proteins. J Bone Joint Surg4:235-241.
14.
McKee MD, Martineau-Doize B., Warshawsky H. (1986). Penetration of various molecular weight proteins into the enamel organ and enamel of the rat incisor. Arch Oral Biol31:287-296.
15.
Menanteau J., Gregoire M., Daculsi G., Jans I. ( 1987). In vitro albumin binding on apatite crystals from developing enamel. Bone Mineral3:137-141.
16.
Ogata Y., Shimokawa H., Sasaki S. (1988). Purification, characterisation and biosynthesis of bovine enamelins. Calcif Tissue Int43:389-399.
17.
Overall CM, Limeback H. (1988). Ciba Foundation Symposium. Identification and characterisation of enamel proteinases isolated from developing enamel. Biochem J256:965-972.
18.
Owen M., Triffit JT, Melick RA (1973). Albumin in bone. In: Elliot K, Fitzsimons DW, editors. Hard tissue growth, repair and remineralisation. Amsterdam (The Netherlands): Elsevier Science, 273-293.
19.
Robinson C., Briggs HD, Atkinson PJ (1981). Histology of enamel organ and chemical composition of adjacent enamel in rat incisors. Calcif Tissue Int33:513-520.
20.
Robinson C., Fuchs P., Deutsch D., Weatherell JA (1978). Four chemically distinct stages in developing enamel from bovine incisor teeth. Caries Res12:1-11.
21.
Robinson C., Kirkham J. (1984). Is the rat incisor typical? INSERM125 :377-386.
22.
Robinson C., Kirkham J. (1985). The dynamics of amelogenesis as revealed by protein compositional studies. In: Butler WT, editor. The chemistry and biology of mineralized tissues. Birmingham (AL): Ebsco Media Inc., 248-263.
23.
Robinson C., Kirkham J., Fincham A. (1989b). The enamelin non/amelogenin problem. A brief review. Connect Tissue Res22:93-100.
24.
Robinson C., Kirkham J., Stonehouse NJ, Shore RC (1989a). Control of crystal growth during enamel maturation . Connect Tissue Res22 :139-145.
25.
Robinson C., Shore RC, Kirkham J., Stonehouse NJ (1990). Extracellular processing of enamel matrix proteins and the control of crystal growth. J Biol Buccale18:355-361.
26.
Small BW, Murray JJ (1978). Enamel opacities: prevalence, classifications and aetiological considerations. J Dent6:33-42.
27.
Strawich E., Glimcher MJ (1990). Tooth "enamelins" identified as mainly serum albumin . Eur J Biochem191:47-56.
28.
Thomas M., Leaver AG (1975). Identification and estimation of plasma proteins in human dentine. Arch Oral Biol20:217-218.
29.
Towbin H., Staehelin T., Gordon J. (1979). Electrophoretic transfer of proteins from polyacrylamide gels to nitrocellulose sheets: procedure and some applications. Proc Natl Acad Sci USA76:4350-4354.
30.
Warshawsky H., Bai P., Nanci A., Josephsen K. (1984). Morphological visualisation of the two categories of enamel proteins in relation to the crystals of rat incisor enamel. In: Fearnhead RW, Suga S, editors. Tooth enamel IV. Amsterdam (The Netherlands): Elsevier, 177-182.
31.
Witkop CJ (1989). Amelogenesis imperfecta, dentinogenesis imperfecta and dentin dysplasia revisited: problems in classification. J Oral Pathol17:547-553.
