Morre, D. James , Morre, Dorothy M. , Jiang, Ziying , Hignite, Heather .
Circadian Timing Inheresnt in the Structure of Water.
Deuterium oxide (heavy water) alters the period length of the biological clock (Bruce and Pittendrigh, 1960, J. Cell. Comp. Physiol. 56: 256). Organisms grown in heavy water have a circadian day of about 30 h compared to the normal 24 h. A growth-related and time-keeping protein, initially discovered in plants (D. J. MorrĂ© and D. M. MorrĂ©,, 1998), appears to function as the core oscillator of the circadian biological clock. The protein, a cell-surface NADH oxidase (ECTO-NOX) with protein disulfide-thiol interchange activity, exhibits a recurring set of oscillation with a period length of 24 min (repeats 60 times over 24 h to generate the normal circadian day). The period length of 24 min is independent of temperature (temperature compensated and is entrainable by light and melatonin. The oscillations depend upon the presence of copper and are recapitulated by copper compounds (i.e., CuCl2) in solution. D2O treatment increases the period length from 24 min to 30 min and exerts a similar effect on aqueous copper (II) solutions. Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy and Fourier Transfer Infrared (FTIR) analyses of copper-associated water of hydration reveal similar patterns of oscillations that correlate with positional changes between the copper and the water oxygens. That the oscillations are the result of physical rather than chemical events provides a rational explanation for the temperature independence of the period length of clock-related (circadian) phenomena. The pattern is apparently inherent in the elongated octahedral structure of the copperII aqua ion [CuCl2(H2O) ] as determined by periodic variations in the ratios of ortho and para nuclear spins of the paired hydrogen atoms of the bound water or D2O.
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1 - Purdue University, Medicinal Chemistry & Molecular Pharmacology, 201 S. University Street, West Lafayette, Indiana, 47907-2064, Tippecanoe
2 - Purdue University, Foods & Nutrition
3 - Purdue University, Medicinal Chemistry & Molecular Pharmacology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM