Zimmerman S B, Harrison B
Proc Natl Acad Sci U S A. 1987 Apr;84(7):1871-5. doi: 10.1073/pnas.84.7.1871.
Macromolecular crowding extends the range of ionic conditions supporting high DNA polymerase reaction rates. Reactions tested were nick-translation and gap-filling by DNA polymerase I of Escherichia coli, nuclease and polymerase activities of the large fragment of that polymerase, and polymerization by the T4 DNA polymerase. For all of these reactions, high concentrations of nonspecific polymers increased enzymatic activity under otherwise inhibitory conditions resulting from relatively high ionic strength. The primary mechanism of the polymer effect seems to be to increase the binding of polymerase to DNA. We suggest that this effect on protein-DNA complexes is only one example of a general "metabolic buffering" action of crowded solutions on a variety of macromolecular interactions.
大分子拥挤效应扩展了支持高DNA聚合酶反应速率的离子条件范围。所测试的反应包括大肠杆菌DNA聚合酶I的切口平移和缺口填补、该聚合酶大片段的核酸酶和聚合酶活性以及T4 DNA聚合酶的聚合反应。对于所有这些反应，在相对高离子强度导致的抑制性条件下，高浓度的非特异性聚合物会增加酶活性。聚合物效应的主要机制似乎是增加聚合酶与DNA的结合。我们认为，这种对蛋白质-DNA复合物的影响只是拥挤溶液对各种大分子相互作用的一般“代谢缓冲”作用的一个例子。
