PHOTOLABILE 1-(2-NITROPHENYL)ETHYL PHOSPHATE-ESTERS OF ADENINE-NUCLEOTIDE ANALOGS - SYNTHESIS AND MECHANISM OF PHOTOLYSIS
PHOTOLABILE 1-(2-NITROPHENYL)ETHYL PHOSPHATE-ESTERS OF ADENINE-NUCLEOTIDE ANALOGS - SYNTHESIS AND MECHANISM OF PHOTOLYSIS
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DOI：
10.1021/ja00229a036
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发表时间：
1988-10-12
影响因子：
15
通讯作者：
TRENTHAM, DR
中科院分区：
文献类型：
--
作者：
WALKER, JW;REID, GP;TRENTHAM, DR
描述了制备光不稳定的磷酸酯和硫代磷酸酯化合物的1-（2-硝基苯基）乙酯的一般方法。该方法是基于一种新的烷基化剂，1-（2-硝基苯基）重氮乙烷的弱电离磷酸基团的选择性烷基化。ATP和广泛使用的ATP的结构类似物，5“-腺苷酰亚胺二磷酸（ATP（β，.γ NH））和腺苷5“-（3-硫代三磷酸）（ATP（γ S））在末端（γ）烷基化。磷酸基团。ATP（γ S）在氧或硫上以大约相等的量烷基化。利用激光脉冲光解技术，在pH值接近中性的水溶液中，对β 3 -1-（2-硝基苯基）乙基腺苷5“-三磷酸（俗称“笼状ATP”）的光解进行了光谱分析。分别监测三种产物ATP、2-亚硝基苯乙酮和H+的形成动力学，以及推测为酸-硝基化合物的中间体的形成和衰减动力学（表观ε 406 nm = 9.1 × 106 nm）。103 M-1 cm-1）。对于在3 mM MgCl 3存在下的笼状ATP，酸性硝基中间体和H+首先在> 105 s-1形成，然后在pH 7.1，21 ℃，86 s-1时中间体衰变。离子强度0.18M。ATP，监测的生化分析，和2-亚硝基苯乙酮，监测的特征吸收带在740 nm处，同时形成的衰减的中间体在所有条件下测试。因此，酸-硝基中间体的衰变速率被用作核苷酸类似物从其光不稳定前体中释放的速率的量度。在pH 7.1、0.18M离子强度和21 ℃下，C的速率常数范围为35至250 s-1，并显示了类似的依赖于pH的笼ATP。1-（2-硝基苯基）乙基磷酸酯的稳态量子产率在0.49-0.63的范围内。2-亚硝基苯乙酮对生物材料的有害作用可以通过硫醇的存在来避免。二硫苏糖醇和2-亚硝基苯乙酮的反应动力学用两步法描述，第一步的速率常数为3.5 × 10 - 4。在pH 7.0，21 ℃，103 M-1 s-1和第二个45 s-1时，离子强度0.18M。
A general method is described for preparing photolabile 1-(2-nitrophenyl)ethyl esters of phosphate and thiophosphate compounds. The method is based on selective alkylation of weakly ionizing phosphate groups by a new alkylating agent, 1-(2-nitrophenyl)diazoethane. ATP and the widely used structural analogues of ATP, 5''-adenylyl imidodiphosphate (ATP(.beta.,.gamma.NH)) and adenosine 5''-(3-thiotriphosphate) (ATP(.gamma.S)), were alkylated on the temrinal (.gamma.) phosphate group. ATP(.gamma.S) was alkylated on oxygen or on sulfur in approximately equal amounts. Photolysis of P3-1-(2-nitrophenyl)ethyladenosine 5''-triphosphate, commonly called "caged ATP", was analyzed spectroscopically at pH values close to neutral in aqueous solvents by use of laser pulse photolysis. The kinetics of formation of the three products, ATP, 2-nitrosoacetophenone, and H+, were each monitored, as well as the kinetics of formation and decay of an intermediate presumed to be an aci-nitro compound (apparent.epsilon.406nm = 9.1 .times. 103 M-1 cm-1). For caged ATP in the presence of 3 mM MgCl3, the aci-nitro intermediate and H+ formed first at > 105 s-1 followed by the decay of the intermediate at 86 s-1 at pH 7.1, 21.degree. C, and ionic strength 0.18 M. ATP, monitored by a biochemical assay, and 2-nitrosoacetophenone, monitored by a characteristic absorption band at 740 nm, were formed simultaneously with the decay of the intermediate under all conditions tested. The rate of decay of the aci-nitro intermediate was therefore used as a measure of the rate of release of the nucleotide analogues from their photolabile precursors. At pH 7.1, 0.18 M ionic strength, and 21.degree. C the rate constants ranged from 35 to 250 s-1 and displayed a similar dependence on pH as caged ATP. The steady-state quantum yields of the 1-(2-nitrophenyl)ethyl phosphate esters were in the range 0.49-0.63. The deleterious effect of 2-nitrosoacetophenone on biological materials can be avoided by having thiols present. The reaction kinetics of dithiothereitol and 2-nitrosoacetophenone was described by a two-step process, the first step having a rate constant of 3.5 .times. 103 M-1 s-1 and the second 45 s-1 at pH 7.0, 21.degree. C, and ionic strength 0.18 M.