[Extraction and Characterization of dentin phosphophoryn from human embryo].
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%).


CONCLUSIONS
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.
West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Wei
W
Dong
Xue-dong
XD
Zhou
Jing-yi
JY
Zhang
D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D003648:Decalcification Technique; D003804:Dentin / Q000737:chemistry*; D004492:Edetic Acid; D004591:Electrophoresis, Polyacrylamide Gel; D005333:Fetus; D006801:Humans; D010750:Phosphoproteins / Q000737:chemistry / Q000302:isolation & purification*
D000596:Amino Acids; D010750:Phosphoproteins; C017630:phosphophoryn; D004492:Edetic Acid