pH triggered self-assembly of native and recombinant amelogenins under physiological pH and temperature in vitro.
Self-assembly of the extracellular matrix protein amelogenin is believed to play an essential role in regulating the growth and organization of enamel crystals during enamel formation. This study examines the effect of temperature and pH on amelogenin self-assembly under physiological pH conditions in vitro, using dynamic light scattering, turbidity measurements, and transmission electron microscopy. Full-length recombinant amelogenins from mouse (rM179) and pig (rP172) were investigated, along with proteolytic cleavage products (rM166 and native P148) lacking the hydrophilic C-terminus of parent molecules. Results indicated that the self-assembly of full-length amelogenin is primarily triggered by pH in the temperature range from 13 to 37 degrees C and not by temperature. Furthermore, very large assemblies of all proteins studied formed through the rearrangement of similarly sized nanospherical particles, although at different pH values: pH 7.7 (P148), pH 7.5 (rM166), pH 7.2 (rP172), and pH 7.2 (rM179). Structural differences were also observed. The full-length molecules formed apparently tightly connected elongated, high-aspect ratio assemblies comprised of small spheres, while the amelogenin cleavage products appeared as loosely associated spherical particles, suggesting that the hydrophilic C-terminus plays an essential role in higher-order amelogenin assembly. Hence, tightly controlled pH values during secretory amelogenesis may serve to regulate the functions of both full-length and cleaved amelogenins.
Wiedemann-Bidlack
Felicitas B
FB
Department of Biomineralization, The Forsyth Institute, 140 The Fenway, Boston, MA 02115-3782, USA.
Beniash
Elia
E
Yamakoshi
Yasuo
Y
Simmer
James P
JP
Margolis
Henry C
HC
D053523:Amelogenin / Q000737:chemistry*; D000595:Amino Acid Sequence; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008027:Light; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry; D012542:Scattering, Radiation; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D053523:Amelogenin; D011994:Recombinant Proteins
J Biol Chem. 2004 Sep 24;279(39):40263-6
15299015
J Dent Res. 1965 Nov-Dec;44(6):Suppl:1119-22
5216239
J Bone Miner Res. 1997 Feb;12(2):221-7
9041053
Calcif Tissue Int. 1987 Nov;41(5):281-9
2825935
Calcif Tissue Int. 1987 Aug;41(2):86-94
3115550
J Struct Biol. 2005 Sep;151(3):239-49
16125972
J Struct Biol. 2000 Jul;131(1):27-37
10945967
Arch Oral Biol. 2001 Feb;46(2):173-83
11163325
Ciba Found Symp. 1997;205:118-30; discussion 130-4
9189621
J Struct Biol. 1994 Mar-Apr;112(2):103-9
8060728
J Cell Biol. 1964 Dec;23:447-97
14245432
J Dent Res. 1996 Oct;75(10):1728-34
8955666
Crit Rev Oral Biol Med. 1995;6(2):84-108
7548623
J Struct Biol. 1999 Jun 1;126(1):42-51
10329487
J Biol Chem. 2001 Aug 24;276(34):31871-5
11406633
Eur J Oral Sci. 2006 May;114 Suppl 1:297-303; discussion 327-9, 382
16674702
Connect Tissue Res. 1998;38(1-4):101-11; discussion 139-45
11063019
Arch Oral Biol. 2004 Aug;49(8):595-605
15196977
Eur J Oral Sci. 2006 May;114 Suppl 1:308-14; discussion 327-9, 382
16674704
Connect Tissue Res. 1998;38(1-4):237-40; discussion 241-6
11063031
J Dent Res. 1998 Jun;77(6):1388-96
9649167
Connect Tissue Res. 1995;32(1-4):119-24
7554907
Ciba Found Symp. 1997;205:187-97; discussion 197-9
9189625
Structure. 1994 Jul 15;2(7):641-9
7922041
Connect Tissue Res. 1996;35(1-4):151-6
9084653
Biopolymers. 2006 Oct 5;83(2):148-58
16718679
Adv Dent Res. 1996 Nov;10(2):159-69
9206332
Biopolymers. 1998 Oct 5;46(4):225-38
9715666
Orthod Craniofac Res. 2005 Nov;8(4):232-8
16238603
Connect Tissue Res. 1998;38(1-4):189-99; discussion 201-5
11063027
Calcif Tissue Int. 1984 Sep;36(5):550-5
6441627
Biopolymers. 2001 Jun;58(7):606-16
11285557
J Dent Res. 2004 Sep;83(9):698-702
15329375
Connect Tissue Res. 1998;38(1-4):279-86; discussion 295-303
11063035
J Struct Biol. 2000 Dec;132(3):191-200
11243888
Biochem Biophys Res Commun. 1985 Jun 28;129(3):812-8
4015654
Biopolymers. 1994 Oct;34(10):1339-47
7948720
J Struct Biol. 2005 Feb;149(2):182-90
15681234
Science. 2005 Mar 4;307(5714):1450-4
15746422
Angew Chem Int Ed Engl. 2003 May 30;42(21):2350-65
12783497
Calcif Tissue Int. 1994 Jan;54(1):69-75
8118757
Cells Tissues Organs. 2005;181(3-4):196-201
16612085
Crit Rev Oral Biol Med. 1998;9(2):128-61
9603233
J Dent Res. 2006 Sep;85(9):775-93
16931858
Arch Oral Biol. 1991;36(3):227-31
1877895
Biochem Biophys Res Commun. 1992 Nov 16;188(3):1253-60
1445358
EMBO J. 1995 Nov 1;14(21):5224-9
7489712
Connect Tissue Res. 1998;38(1-4):257-67;discussion 295-303
11063033
Calcif Tissue Int. 1994 Apr;54(4):312-9
8062146
J Dent Res. 1979 Mar;58(Spec Issue B):753-64
368095
Nature. 1975 Dec 25;258(5537):772-4
1207767
J Biomed Mater Res. 2001 Jan;54(1):87-95
11077406
J Bone Miner Res. 2005 Feb;20(2):240-9
15647818
J Struct Biol. 1998;122(3):320-7
9774536
Connect Tissue Res. 1995;32(1-4):125-30
7554908
J Struct Biol. 1995 Jul-Aug;115(1):50-9
7577231