Purine catabolism in isolated rat hepatocytes. Influence of coformycin.
Purine catabolism in isolated rat hepatocytes. Influence of coformycin.
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离体大鼠肝细胞中的嘌呤分解代谢。
DOI：
10.1042/bj1880913
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
Hers,HG
中科院分区：
文献类型：
--
作者：
VandenBerghe,G;Bontemps,F;Hers,HG
1.嘌呤核苷酸的催化剂进行了研究，通过化学和放射化学方法在离体大鼠肝细胞，预先与[14 C]腺嘌呤孵育。尿囊素的产量达到32 ± 5nmol/min/g细胞（平均值± s.e.m.）。1小时后，腺嘌呤核苷酸中掺入的放射性损失高达30%。这一降解速率是先前报告的肝脏体内降解速率的数倍。对这种增强的催化剂的解释可能是GTP浓度的降低。2.在大鼠肝高速培养上清中，0.1 μ m-共形霉素对腺苷脱氨酶有最大的抑制作用。AMP脱氨酶的活性（在相同制剂中存在其刺激剂ATP的情况下测量）以及部分纯化的酶的活性（在加入其生理抑制剂GTP和Pi后测量）需要50 μ m-共形霉素才能达到最大抑制。3.加入0.1 μ m-共形霉素对分离肝细胞的尿囊素产量没有影响，但抑制AMP脱氨酶的共形霉素浓度会降低尿囊素产量。用50 μ m-共形霉素使尿囊素的产量减少85%，[14C]腺嘌呤核苷酸形成放射性尿囊素的反应完全被抑制。4.在存在或不存在0.1 μ m-共形霉素的情况下，向孵育培养基中加入果糖（1mg/ml）引起ATP快速降解，ADP和AMP没有同等增加，随后IMP和尿囊素产生速率瞬时增加;腺苷未检测到。在50 μ m-共形霉素存在下，果糖诱导的ATP分解没有改变，但腺嘌呤核苷酸库的消耗进行得慢得多，尿囊素的产生速率仅略有增加。未检测到IMP浓度升高，但AMP增加了许多倍，并达到了可溶性5 ′-核苷酸酶参与腺嘌呤核苷酸催化的最可能值。5.这些结果与尿囊素的形成受AMP脱氨酶控制的假设一致。它们进一步证明了5 ′-核苷酸酶对AMP无活性，除非这种核苷酸的浓度上升到非生理值。
1. The catabolism of purine nucleotides was investigated by both chemical and radiochemical methods in isolated rat hepatocytes, previously incubated with [14C]adenine. The production of allantoin reached 32±5nmol/min per g of cells (mean±s.e.m.) and as much as 30% of the radioactivity incorporated in the adenine nucleotides was lost after 1h. This rate of degradation is severalfold in excess over values previously reported to occur in the liverin vivo. An explanation for this enhancement of catabolism may be the decrease in the concentration of GTP. 2. In a high-speed supernatant of rat liver, adenosine deaminase was maximally inhibited by 0.1μm-coformycin. The activity of AMP deaminase, measured in the presence of its stimulator ATP in the same preparation, as well as the activity of the partially purified enzyme, measured after addition of its physiological inhibitors GTP and Pi, required 50μm-coformycin for maximal inhibition. 3. The production of allantoin by isolated hepatocytes was not influenced by the addition of 0.1μm-coformycin, but was decreased by concentrations of coformycin that were inhibitory for AMP deaminase. With 50μm-coformycin the production of allantoin was decreased by 85% and the formation of radioactive allantoin from [14C]adenine nucleotides was completely suppressed. 4. In the presence of 0.1μm-coformycin or in its absence, the addition of fructose (1mg/ml) to the incubation medium caused a rapid degradation of ATP, without equivalent increase in ADP and AMP, followed by transient increases in IMP and in the rate of production of allantoin; adenosine was not detectable. In the presence of 50μm-coformycin, the fructose-induced breakdown of ATP was not modified, but the depletion of the adenine nucleotide pool proceeded much more slowly and the rate of production of allantoin increased only slightly. No rise in IMP concentration could be detected, but AMP increased manyfold and reached values at which a participation of soluble 5′-nucleotidase in the catabolism of adenine nucleotides is most likely. 5. These results are in agreement with the hypothesis that the formation of allantoin is controlled by AMP deaminase. They constitute further evidence that 5′-nucleotidase is inactive on AMP, unless the concentration of this nucleotide rises to unphysiological values.
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大鼠肝脏可溶性5-核苷酸酶的动力学研究。
DOI：
10.1042/bj1620611
发表时间：
1977
期刊：
The Biochemical journal
影响因子：
--
作者：
G. van den Berghe;C. van Pottelsberghe;H. Hers
通讯作者：
H. Hers
核苷抗生素考福霉素和脱氧考福霉素可有效抑制肌肉 5-AMP 脱氨酶。
影响因子：
5.8
作者：
R. Agarwal;R. Parks
通讯作者：
R. Parks
考福霉素对腺苷脱氨酶的抑制模式。
DOI：
--
发表时间：
1967
期刊：
Journal of antibiotics (Tokyo. 1968)
影响因子：
--
作者：
T. Sawa;Y. Fukagawa;I. Homma;T. Takeuchi;H. Umezawa
通讯作者：
H. Umezawa
果糖负荷后肝脏中三磷酸腺苷消耗的机制。
影响因子：
4.1
作者：
G. van den Berghe;M. Bronfman;R. Vanneste;H. Hers
通讯作者：
H. Hers