Lorimer G H
Central Research and Development Department, Dupont Company Experimental Station, Wilmington, Delaware 19880-0402, USA.
FASEB J. 1996 Jan;10(1):5-9. doi: 10.1096/fasebj.10.1.8566548.
In vitro the chaperonin proteins, GroEL and GroES, facilitate the folding of some other proteins under conditions where that process does not occur spontaneously. Using values drawn from a number of such in vitro studies, together with the known rates of in vivo protein synthesis by Escherichia coli and the known quantities of GroEL and GroES in E. coli, an assessment of the general role of these proteins in protein folding in vivo has been made. Three specific cases are examined, where compelling evidence points to the involvement of the chaperonins; the in vivo folding of the bacteriophage coat protein during the burst phase of phage morphogenesis and of Rubisco during chloroplast development and during expression of recombinant Rubisco in E. coli. In each case the maximum in vitro rates are nearly sufficient to account for the observed in vivo rates of formation of the native protein. However, in general, there appears to be sufficient GroEL and GroES to facilitate the folding of no more than 5% of all of the proteins within E. coli.
在体外，伴侣蛋白GroEL和GroES能在某些蛋白质无法自发折叠的条件下促进其折叠。利用多项此类体外研究的数据，结合大肠杆菌体内蛋白质合成的已知速率以及大肠杆菌中GroEL和GroES的已知数量，对这些蛋白质在体内蛋白质折叠中的总体作用进行了评估。研究了三个具体案例，有力证据表明伴侣蛋白参与其中：噬菌体形态发生爆发期噬菌体外壳蛋白的体内折叠、叶绿体发育过程中以及在大肠杆菌中重组核酮糖-1,5-二磷酸羧化酶（Rubisco）表达过程中Rubisco的体内折叠。在每种情况下，体外最大速率几乎足以解释观察到的天然蛋白质在体内的形成速率。然而，总体而言，似乎有足够的GroEL和GroES来促进大肠杆菌中不超过5%的所有蛋白质的折叠。
