Delineation of conformational preferences in human salivary statherin by 1H, 31P NMR and CD studies:: Sequential assignment and structure-function correlations

被引:46
作者
Naganagowda, GA
Gururaja, TL
Levine, MJ [1 ]
机构
[1] SUNY Buffalo, Dept Oral Biol, Buffalo, NY 14214 USA
[2] SUNY Buffalo, Dent Res Inst, Buffalo, NY 14214 USA
关键词
D O I
10.1080/07391102.1998.10508230
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Membrane-induced solution structure of human salivary statherin, a 43 amino acid residue acidic phosphoprotein, has been investigated by two-dimensional proton nuclear magnetic resonance (2D H-1 NMR) spectroscopy. NMR assignments and structural analysis of this phosphoprotein was accomplished by analyzing the pattern of sequential and medium range NOEs, alpha CH chemical shift perturbations and deuterium exchange measurements of the amide proton resonances. The NMR data revealed three distinct structural motifs in the molecule: (1) an alpha-helical structure at the N-terminal domain comprising Asp(1)-Tyr(16), (2) a polyproline type II (PPII) conformation predominantly occurring at the middle proline-rich domain spanning Gly(19)-Gln(35), and (3) a 3(10)-helical structure at the C-terminal Pro(36)-Phe(43) sequence. Presence of a few weak d(alpha N(i, i+2)) NOEs suggests that N-terminus also possesses ;minor population of 3(10)-helical conformation. Of the three secondary structural elements, helical structure formed by the N-terminal residues, Asp(1)-Ile(11) appears to be more rigid as observed by the relatively very slow exchange of amide hydrogens of Glu(5)-Ile(11). P-31 NMR experiments clearly indicated that N-terminal domain of statherin exists mainly in disordered state in water whereas, upon addition of structure stabilizing co-solvent, 2,2,2-trifluorethanol (TFE), it showed a strong propensity for helical conformation. Calcium ion interaction studies suggested that the disordered N-terminal region encompassing the two vicinal phosphoserines is essential for the binding of calcium ions in vivo. Results from the circular dichroism (CD) experiments were found to be consistent with and complimentary to the NMR data and provided an evidence that non-aqueous environment such as TFE, could induce the protein to fold into helical conformation. The findings that the statherin possesses blended solvent sensitive secondary structural elements and the requirement of non-structured N-terminal region under aqueous environment in calcium ion interaction may be invaluable to understand various physiological functions of statherin in the oral fluid.
引用
收藏
页码:91 / 107
页数:17
相关论文
共 64 条
[1]   LEFT-HANDED POLYPROLINE-II HELICES COMMONLY OCCUR IN GLOBULAR-PROTEINS [J].
ADZHUBEI, AA ;
STERNBERG, MJE .
JOURNAL OF MOLECULAR BIOLOGY, 1993, 229 (02) :472-493
[2]   Structural domains of Porphyromonas gingivalis recombinant fimbrillin that mediate binding to salivary proline-rich protein and statherin [J].
Amano, A ;
Sharma, A ;
Lee, JY ;
Sojar, HT ;
Raj, PA ;
Genco, RJ .
INFECTION AND IMMUNITY, 1996, 64 (05) :1631-1637
[3]  
[Anonymous], 1992, Adv. Biophys. Chem
[4]   INHIBITION OF APATITE CRYSTAL-GROWTH BY THE AMINO-TERMINAL SEGMENT OF HUMAN SALIVARY ACIDIC PROLINE-RICH PROTEINS [J].
AOBA, T ;
MORENO, EC ;
HAY, DI .
CALCIFIED TISSUE INTERNATIONAL, 1984, 36 (06) :651-658
[5]   STRUCTURE OF POLY-L-PROLINE 2 [J].
ARNOTT, S ;
DOVER, SD .
ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL CRYSTALLOGRAPHY AND CRYSTAL CHEMISTRY, 1968, B 24 :599-&
[6]   MLEV-17-BASED TWO-DIMENSIONAL HOMONUCLEAR MAGNETIZATION TRANSFER SPECTROSCOPY [J].
BAX, A ;
DAVIS, DG .
JOURNAL OF MAGNETIC RESONANCE, 1985, 65 (02) :355-360
[7]  
BENNICK A, 1982, MOL CELL BIOCHEM, V45, P83
[8]   NATURE OF THE HYDROXYAPATITE-BINDING SITE IN SALIVARY ACIDIC PROLINE-RICH PROTEINS [J].
BENNICK, A ;
CANNON, M ;
MADAPALLIMATTAM, G .
BIOCHEMICAL JOURNAL, 1979, 183 (01) :115-126
[9]  
BENNICK A, 1981, J BIOL CHEM, V256, P4741
[10]   CONSIDERATION OF POSSIBILITY THAT SLOW STEP IN PROTEIN DENATURATION REACTIONS IS DUE TO CIS-TRANS ISOMERISM OF PROLINE RESIDUES [J].
BRANDTS, JF ;
HALVORSON, HR ;
BRENNAN, M .
BIOCHEMISTRY, 1975, 14 (22) :4953-4963