EDTA soluble protein of human mature normal enamel

Abstract

Pure human mature enamel was prepared using a careful microdissection technique. After EDTA dissolution, the soluble proteins were recovered representing a concentration of 0.035% in the initial enamel. When the samples were analyzed with polyacrylamide gel electrophoresis, Coomassie Brilliant Blue staining revealed only one sharp fast migrating band, whereas o-toluidine blue, methylene blue, Amido Black 10B, and pyronine red G showed a thin double band at the same migration distance. Ultracentrifugation studies suggested that the proteins were of low molecular weight or of weak density. Absorption spectra showed a strong absorbance at 260 nm. After hydrolysis, amino acid analyses yielded a composition of 25% Gly, 13.5% Glu, 11% Ser, and 11% Pro. Cysteine measured as cysteic acid was present at 2%, and 2% hydroxyproline was found. A carbohydrate content of 15% was estimated by the anthrone method. Glucose, galactose, mannose, and fucose, identified through gas chromatography, were in a molar ratio of 9:4:3:1. Thus the organic matrix of adult human enamel consists of one or possibly two acidic glycoproteins.

Neonatal hamster molar tooth development: Extraction and characterization of amelogenins, enamelins, and soluble dentin proteins

“…A high molecular weight (160,000-200,000 daltons) Stains-All-positive protein band was observed in all hamster enamelin fractions on SDS gels. The amino acid composition of this partially purified hamster enamel crystal protein was comparable to that of adult bovine and human enamel matrix proteins [30,32].…”

The Role of Fluoride and Casein Phosphopeptide/Amorphous Calcium Phosphate in the Prevention of Erosive/Abrasive Wear in an in vitro Model Using Hydrochloric Acid

“…In the present study, the acid was not admixed with the proteolytic enzyme pepsin, as it had been in a previous study . The amount of organic matrix in enamel is very low (0.035%) [Belcourt and Gillmeth, 1979] and even for dentine, no influence of pepsin admixture on the erosive/abrasive tooth wear could be observed. Toothbrushing was performed before erosion and 1 h after the last erosive attack per day to follow the recommendations made for patients suffering from erosion [Lazarchik and Filler, 1997;Wiegand et al, 2008], although there are studies showing that the period between erosion and toothbrushing has only a minor effect on the erosion/ abrasion tooth wear .…”

Ethylenediaminetetraacetic Acid Insoluble Protein of Adult Human Enamel

“…This suggests that all the protein present in mature enamel is tightly bound to apatite crystals, a characteristic typical of the enamelin class of enamel proteins [Termine et al, 1980]. The guanidine-EDTA soluble fraction contained a glycoprotein of low molecular weight (~ 2,000-3,000) having an amino acid composition including the presence of hydroxyproline almost identical to that described previously using an isola tion procedure employing only EDTA [Belcourt and Gillmeth, 1979], The guanidine-EDTA insoluble residue contained lactic acid-soluble glycoprotein similar in size and amino acid composition to that which became solubilized in EDTA under the same extraction conditions. The amino acid compositions of both the HET-E and the LAC protein fractions are similar to the data of Robinson et al [1975] for mature human enamel 'tuft' protein prepa rations, although the analyses of this study (table I) showed markedly higher propor tions of glycine and serine, and higher pro portions of hydroxyproline.…”

“…Concomitant with this change, the amino acid composi tion of the enamel organic matrix undergoes substantial modification from an early ma trix containing high percentages of glutamic acid, proline, leucine and histidine to a fully mineralized matrix having substantially in creased proportions of aspartic acid, serine and glycine [Eastoe, 1960[Eastoe, , 1963Glimcher et al, 1961;Fincham, 1971Fincham, , 1980Eggert et al, 1973;Robinson et al, 1977], In a previous study [Belcourt and Gillmeth, 1979] it was found that an acidic gly-coprotein of low molecular weight was solu bilized after extraction of pure normal ma ture human enamel in 0.4 M EDTA, pH 7.2. However, an insoluble residue always remained, even after extensive EDTA ex traction.…”