Journal - Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition (China )

Abstract :

OBJECTIVE: To extract the dentin phosphophoryn (DPP) from human embryo and analyze its characteristic. METHODS: Eight dental germs collected from the human embryo at the gestational age of 25-33 weeks were decalcified in 0.25 mol/L EDTA until Ca2+ was undetectable in the solution, and then were dissociated by 4 mol/L guanidine hydrochloride. Characterization of the extracts included SDS-PAGE for its molecular weight and amino acid analysis. RESULTS: SDS-PAGE showed the relative molecular mass of the DPP to be 140 x 10(3), 125 x 10(3) and 76 x 10(3). Amino acid analysis revealed the DPP contained mainly Asp (41.2%) and Ser (28.5%). CONCLUSION: Dentin phosphophoryn can be extracted from human embryo by using 0.25 mol/L EDTA and 4 mol/L guanidine hydrochloride. Its relative molecular mass was determined to be 76 x 10(3)-140 x 10(3), and its constitution characterized by abundant Asp and Ser resembles that of DPP extracted from the teeth with immature apices.