[Extraction and Characterization of dentin phosphophoryn from human embryo]
Wei Dong1, Xue-dong Zhou, Jing-yi Zhang
1West China School of Stomatology, Sichuan University, Chengdu 610041, China.
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.
