Glu46 donates a proton to the 4-hydroxycinnamate anion chromophore during the photocycle of photoactive yellow protein

被引:173
作者
Xie, AH
Hoff, WD
Kroon, AR
Hellingwerf, KJ
机构
[1] UNIV TEXAS,SCH MED,HLTH SCI CTR,DEPT MICROBIOL & MOL GENET,HOUSTON,TX 77030
[2] UNIV AMSTERDAM,EC SLATER INST BIOCHEM RES,DEPT MICROBIOL,NL-1018 WS AMSTERDAM,NETHERLANDS
关键词
D O I
10.1021/bi9623035
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
Photoactive yellow protein (PYP) is a photoreceptor containing a unique 4-hydroxycinnamic acid (pCA) chromophore. The trans to cis photoisomerization of this chromophore activates a photocycle involving first a short-lived red-shifted intermediate (pR), then a long-lived blue-shifted intermediate (pB), and finally recovery of the original receptor state (pG). The pCA chromophore is deprotonated in pG and protonated in pB, but the proton donor for this process has not yet been identified. Here we report the first FTIR spectroscopic data on pc, pR, and pB. The IR difference signals in the carbonyl stretching region of COOH groups (1700-1800 cm(-1)) reveal that a buried carboxylic group close to the chromophore (i) is protonated in pG, (ii) develops a stronger hydrogen bonding in pR, and (iii) becomes deprotonated in pB. These signals are unambiguously assigned to Glu46, on the basis of the IR data and the 1.4 Angstrom X-ray structure of PYP [Borgstahl et al. (1995) Biochemistry 34, 6278-6287]. Our data demonstrate that in pR Glu46 remains in hydrogen bonding contact with the negatively charged phenolic oxygen of pCA after chromophore photoisomerization. This strongly implies that the chromophore is isomerized to the 7-cis 9-s-trans conformation in pR, resulting from co-isomerization of both the C-7=C-8 and C-9-C-10 bands. In the pR to pB transition, Glu46 becomes deprotonated, concomitant with chromophore protonation, Therefore, we conclude that Glu46 functions as the proton donor for the protonation of PCA during the PYP photocycle. We propose a molecular mechanism in which intramolecular proton transfer in PYP leads to global protein conformational changes involved in signal transduction.
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收藏
页码:14671 / 14678
页数:8
相关论文
共 34 条
[1]   COMPLETE CHEMICAL-STRUCTURE OF PHOTOACTIVE YELLOW PROTEIN - NOVEL THIOESTER-LINKED 4-HYDROXYCINNAMYL CHROMOPHORE AND PHOTOCYCLE CHEMIST [J].
BACA, M ;
BORGSTAHL, GEO ;
BOISSINOT, M ;
BURKE, PM ;
WILLIAMS, DR ;
SLATER, KA ;
GETZOFF, ED .
BIOCHEMISTRY, 1994, 33 (48) :14369-14377
[2]   1.4 ANGSTROM STRUCTURE OF PHOTOACTIVE YELLOW PROTEIN, A CYTOSOLIC PHOTORECEPTOR - UNUSUAL FOLD, ACTIVE-SITE, AND CHROMOPHORE [J].
BORGSTAHL, GEO ;
WILLIAMS, DR ;
GETZOFF, ED .
BIOCHEMISTRY, 1995, 34 (19) :6278-6287
[3]   DOMINANT FORCES IN PROTEIN FOLDING [J].
DILL, KA .
BIOCHEMISTRY, 1990, 29 (31) :7133-7155
[4]  
DOLLINGER G, 1986, METHOD ENZYMOL, V127, P649
[5]   PROTEINS AND PRESSURE [J].
FRAUENFELDER, H ;
ALBERDING, NA ;
ANSARI, A ;
BRAUNSTEIN, D ;
COWEN, BR ;
HONG, MK ;
IBEN, IET ;
JOHNSON, JB ;
LUCK, S ;
MARDEN, MC ;
MOURANT, JR ;
ORMOS, P ;
REINISCH, L ;
SCHOLL, R ;
SCHULTE, A ;
SHYAMSUNDER, E ;
SORENSEN, LB ;
STEINBACH, PJ ;
XIE, AH ;
YOUNG, RD ;
YUE, KT .
JOURNAL OF PHYSICAL CHEMISTRY, 1990, 94 (03) :1024-1037
[6]   LOW-TEMPERATURE ABSORBENCY AND FLUORESCENCE SPECTROSCOPY OF THE PHOTOACTIVE YELLOW PROTEIN FROM ECTOTHIORHODOSPIRA-HALOPHILA [J].
HOFF, WD ;
KWA, SLS ;
VANGRONDELLE, R ;
HELLINGWERF, KJ .
PHOTOCHEMISTRY AND PHOTOBIOLOGY, 1992, 56 (04) :529-539
[7]   Chemical reactivity and spectroscopy of the thiol ester-linked p-coumaric acid chromophore in the photoactive yellow protein from Ectothiorhodospira halophila [J].
Hoff, WD ;
Devreese, B ;
Fokkens, R ;
NugterenRoodzant, IM ;
VanBeeumen, J ;
Nibbering, N ;
Hellingwerf, KJ .
BIOCHEMISTRY, 1996, 35 (04) :1274-1281
[8]   THIOL ESTER-LINKED P-COUMARIC ACID AS A NEW PHOTOACTIVE PROSTHETIC GROUP IN A PROTEIN WITH RHODOPSIN-LIKE PHOTOCHEMISTRY [J].
HOFF, WD ;
DUX, P ;
HARD, K ;
DEVREESE, B ;
NUGTERENROODZANT, IM ;
CRIELAARD, W ;
BOELENS, R ;
KAPTEIN, R ;
VANBEEUMEN, J ;
HELLINGWERF, KJ .
BIOCHEMISTRY, 1994, 33 (47) :13959-13962
[9]   MEASUREMENT AND GLOBAL ANALYSIS OF THE ABSORBENCY CHANGES IN THE PHOTOCYCLE OF THE PHOTOACTIVE YELLOW PROTEIN FROM ECTOTHIORHODOSPIRA-HALOPHILA [J].
HOFF, WD ;
VANSTOKKUM, IHM ;
VANRAMESDONK, HJ ;
VANBREDERODE, ME ;
BROUWER, AM ;
FITCH, JC ;
MEYER, TE ;
VANGRONDELLE, R ;
HELLINGWERF, KJ .
BIOPHYSICAL JOURNAL, 1994, 67 (04) :1691-1705
[10]   FREE-ENERGY BALANCE IN PROTEIN-FOLDING [J].
HONIG, B ;
YANG, AS .
ADVANCES IN PROTEIN CHEMISTRY, VOL 46: PROTEIN STABILITY, 1995, 46 :27-58