Butterman M, Tietz D, Orbán L, Chrambach A
Section on Macromolecular Analysis, National Institute of Child Health and Human Development, Bethesda, MD 20892.
Electrophoresis. 1988 Jul;9(7):293-8. doi: 10.1002/elps.1150090702.
In contrast to Ferguson plots based on relative mobilities, Ferguson plots of proteins in polyacrylamide gel electrophoresis based on their absolute mobilities were found to be linear under unusual polymerization conditions which yield relatively wide gel fibers and a low total fiber length per unit weight, but not under previously and commonly used conditions. These linear Ferguson plots in gels of 1, 3 and 5% crosslinking intersect at a single gel concentration between 1 and 2% T (M-point). It is postulated that the measure of free mobility of the proteins is the M-point, and not the intercept of their Ferguson plots with the mobility axis as assumed previously. This postulate abolishes the well-known paradoxical interpretation of the increase with %C of the linearly extrapolated intercept of the Ferguson plot with the log(mobility) axis (designated Yo) in terms of free mobility. The postulate is also compatible with the interpretation of the points of intersection of the Ferguson plots of oligomeric series of proteins at finite gel concentrations (designated mu-points) as their common free mobilities.
与基于相对迁移率的弗格森图不同，在产生相对较宽凝胶纤维且单位重量总纤维长度较低的异常聚合条件下，聚丙烯酰胺凝胶电泳中基于蛋白质绝对迁移率的弗格森图呈线性，但在先前常用的条件下则不然。这些在1%、3%和5%交联度凝胶中的线性弗格森图在1%至2%T（M点）之间的单一凝胶浓度处相交。据推测，蛋白质自由迁移率的度量是M点，而非如先前假设的那样是其弗格森图与迁移率轴的截距。这一假设消除了对弗格森图与对数（迁移率）轴的线性外推截距（称为Yo）随%C增加的著名矛盾解释，该解释涉及自由迁移率。这一假设也与将有限凝胶浓度下蛋白质寡聚体系列的弗格森图交点（称为μ点）解释为其共同自由迁移率相一致。
