• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.1001-1003
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• 1994

A series of phosphodiesters of p-nitrophenyl phosphoryl derivatives were synthesized and used as a model substrate for phospholipase D (PLD). The phosphodiester substrates were synthesized from p-nitrophenyl phosphorodichloridate and corresponding alcohols with different chain lengths and polar groups. To measure the activity of PLD, either spectroscopic method for p-nitrophenol or pH-stat titration method was employed. For each substrate, effects of substrate concentration, pH, and $Ca^{2+}$ ion were examined. The kinetic parameters $V_{max}$ for the different substrates were varied depending on the chain lengths or charge of the alcohols. No calcium effect was observed in the hydrolysis of neutral and negatively charged alcohol derivatives, while positively charged choline derivative showed a strong $Ca^{2+}$ ion dependence.

• Applied Biological Chemistry
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• 제37권6호
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• pp.447-450
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• 1994

RNA의 가수분해시에 생성되는 cyclic phosphate 중간체의 모델 화합물인 ethylene phosphate의 P-O결합 분해속도 상수는 $100^{\circ}C$ 에서 $k=3{\times}10^{-7}s^{-1}({\Delta}H{\neq}=24\;kcal,\;{\Delta}S{\neq}=25.5\;eu)$이었으며 DNA모델 화합물인 dimethylphosphate는 $150^{\circ}C$에서 $1{\times}10^{-11}s^{-1}({\Delta}H{\neq}=36\;kcal,\;{\Delta}S{\neq}=25.5\;eu)$이었다. RNA모델 화합물인 hydroxyethylmethylphosphate의 가수분해는 dimethylphosphate의 C-O결합이 가수분해되는 반응속도와 비교될 만한 정도의 반응속도가 관측되었다.

• 한국자기공명학회논문지
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• 제3권1호
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• pp.1-11
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• 1999

Localized in vivo 31P NMR spectroscopy was applied to evaluate the postmortem catabolism of high energy phosphates in rabbit skeletal muscle tissue. In the premortem processes all of the important high energy phosphate metabolites were characterized, and particularly phosphocreatine (PCr) resonance signal was the strongest. In the immediate phases of the postmortem processes the signal intensities of PCr, phosphomonoesters (PME), phosphodiesters(PDE), $\alpha$-, $\beta$- and ${\gamma}$-adenosine triphosphate (ATP) resonance began to decrease while the signal intensity of inorganic phosphorus (Pi) resonance began to increase. The present study suggests that localized in vivo 31P NMR spectroscopy may provide more precise biochemical information of the early postmortem period based on the metabolic alterations of phosphate. The unique ability of localized in vivo 31P NMR spectroscopy to offer noninvasive information about tissue biochemistry in animals as well as human may have an impact on thanatochronology and medicolegal science.