Schmidt G, Cohen M P, DeMarco P
Mol Cell Biochem. 1975 Mar 27;6(3):185-94. doi: 10.1007/BF01732077.
The biphasic nature of the time course of the action of staphylococcal nuclease on thymus nucleohistone was confirmed by studying the hydrolysis of this nucleoprotein at various enzyme concentrations. The transition from the rapid first to the sluggish second phase of the time course was particularly distinct at the highest enzyme concentrations. The rapid initial phase of the hydrolysis curve leveled off sharply when between 60 and 65 per cent of the total TNH phosphorus had been converted to acid-soluble phosphorus compounds. The insoluble complexes of TNH with protamines were found to be very resistant against the action of staphylococcal nuclease. The time course of the action of staphylococcal nuclease on a commercial nucleoprotamine of salmon testicles was found to become very sluggish when between 35 and 40 per cent of its total phosphorus had been converted to acid-soluble phosphorus compounds. When nucleoprotamines prepared in the laboratory from the secreted sperm cell suspension of Brown Brook Trout were digested with staphylococcal nuclease, only between 15 and 20 per cent of the total phosphorus were cleaved to acid-soluble phosphorus compounds during the rapid phase of the nuclease action. The respective values for the phosphorus fractions available for magnesium-binding and those susceptible to the rapid cleavage by staphylococcal nuclease were found to be very similar.
通过研究在不同酶浓度下该核蛋白的水解情况，证实了葡萄球菌核酸酶作用于胸腺核组蛋白的时间进程具有双相性。在最高酶浓度下，时间进程从快速的第一阶段向缓慢的第二阶段的转变尤为明显。当总TNH磷的60%至65%已转化为酸溶性磷化合物时，水解曲线的快速初始阶段急剧趋于平稳。发现TNH与鱼精蛋白的不溶性复合物对葡萄球菌核酸酶的作用具有很强的抗性。当鲑鱼睾丸的商业核鱼精蛋白中总磷的35%至40%已转化为酸溶性磷化合物时，发现葡萄球菌核酸酶作用于该核鱼精蛋白的时间进程变得非常缓慢。当用葡萄球菌核酸酶消化实验室从褐溪鳟分泌精子细胞悬液制备的核鱼精蛋白时，在核酸酶作用快速阶段，仅15%至20%的总磷被裂解为酸溶性磷化合物。发现可用于镁结合的磷组分以及易被葡萄球菌核酸酶快速裂解的磷组分的相应值非常相似。
