Department of Food Science and Technology, University of California, Davis, California 95616.
Plant Physiol. 1969 Nov;44(11):1574-83. doi: 10.1104/pp.44.11.1574.
Six of the proteolytic enzyme components of Ficus glabrata ficin have been isolated and shown to be chromatographically homogeneous. The molecular weights, the amino acid compositions, the electrophoretic and chromatographic behavior of the tryptic peptides, and the relative specificities of these 6 components have been determined. Within the experimental precision of the methods all 6 components are identical. They also have identical solubilities in sodium chloride and ammonium sulfate solutions. However, they are markedly different in their chromatographic properties. These multiple molecular forms of Ficus glabrata ficin may differ only in their conformational forms (conformers) or they may have minor differences in amino acid sequences which are sufficient to give different conformations and yet not be detected by the usual peptide mapping techniques. At the moment, we favor the latter possibility.
六榕果榕蛋白酶的酶解成分已被分离出来,并显示出具有色谱均一性。测定了这些 6 个成分的分子量、氨基酸组成、胰蛋白酶肽的电泳和色谱行为以及相对特异性。在方法的实验精度内,所有 6 个成分都是相同的。它们在氯化钠和硫酸铵溶液中的溶解度也相同。然而,它们在色谱性质上有显著的差异。六榕果榕蛋白酶的这些多种分子形式可能仅在构象形式(构象体)上有所不同,或者它们在氨基酸序列上有微小的差异,足以产生不同的构象,但无法通过常用的肽图谱技术检测到。目前,我们倾向于后者的可能性。