Araya A, Krauskopf M
Acta Physiol Lat Am. 1976;26(2):97-105.
The influence of buffer, pH, Mg2+, ATP, Na+, K+ and temperature on the extent and rate of aminoacyl-tRNA synthesis was studied with the shark Mustelus mento liver tRNAs and aminoacyl-tRNA synthetases. The optimum pH for the aminoacylation of tRNAMet was 8.3 and for tRNAVal 7.0. For these two tRNAs the Mg2+ optimum was related to the levels of ATP required and to the pH of the reactions. It is suggested that the Mg2+ concentration required for each aminoacylation system reflects the true conditions under which the substrate for the enzyme, the MgATP2- complex, is formed. The effect of monovalent cations was also examined. Val-tRNA synthesis was slightly stimulated up to a concentration of 50 mM NaCl (KCl). Over 100 mM salt, a rapid inhibition was observed. Met-tRNA synthesis behaves differently by being stimulated over a wide range of salt concentrations.
利用星鲨肝脏的tRNA和氨酰-tRNA合成酶，研究了缓冲液、pH值、镁离子、ATP、钠离子、钾离子和温度对氨酰-tRNA合成程度和速率的影响。甲硫氨酸tRNA氨酰化的最适pH值为8.3，缬氨酸tRNA氨酰化的最适pH值为7.0。对于这两种tRNA，镁离子的最适浓度与所需的ATP水平以及反应的pH值有关。有人认为，每个氨酰化系统所需的镁离子浓度反映了酶的底物MgATP2-复合物形成的真实条件。还研究了单价阳离子的作用。高达50 mM NaCl（KCl）浓度时，缬氨酸-tRNA合成受到轻微刺激。超过100 mM盐时，观察到快速抑制作用。甲硫氨酸-tRNA合成在广泛的盐浓度范围内受到刺激，表现不同。
