[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.
Dong
Wei
W
West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Zhou
Xue-dong
XD
Zhang
Jing-yi
JY
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