Institut für Biologie III der Universität Freiburg, Schänzlestraße 1, D-7800, Freiburg, Federal Republic of Germany.
Planta. 1979 Jan;145(2):129-35. doi: 10.1007/BF00388708.
Polyethyleneglycol (PEG) has been used to sediment particulate material from maize coleoptile homogenates at low centrifugal forces. The resuspended sediments were used for N-1-naphthylphthalamic acid (NPA)-binding studies. Binding activity was influenced by monovalent cations in the resuspension medium, but even at concentrations of up to 1.2 M NaCl or 0.5 M LiCl or CsCl, half of the binding activity was still recovered. Binding activity was influenced by divalent cations, because it decreased when Ca(2+) and Mg(2+) ions in the medium were complexed with EDTA. Fractionated sedimentation using increasing concentrations of PEG resulted in two peaks of NPA-binding activity at about 3% and 6% PEG. The 3% peak cintained enzymatic markers for mitochondria and endoplasmatic reticulum while the 6% peak contained NPA-binding activity only. Possible explanations for the bimodal distribution of NPA binding after fractionated PEG precipitation are discussed.
聚乙二醇（PEG）已被用于在低离心力下沉淀玉米胚芽匀浆中的颗粒物质。重新悬浮的沉淀物用于 N-1-萘基邻苯二甲酰亚胺（NPA）结合研究。结合活性受再悬浮介质中的单价阳离子影响，但即使在高达 1.2 M NaCl 或 0.5 M LiCl 或 CsCl 的浓度下，仍有一半的结合活性得以恢复。结合活性受二价阳离子影响，因为当介质中的 Ca(2+)和 Mg(2+)离子与 EDTA 络合时，结合活性会降低。使用递增浓度的 PEG 进行分级沉淀导致 NPA 结合活性在约 3%和 6%PEG 处出现两个峰。3%峰包含线粒体和内质网的酶标记物，而 6%峰仅含有 NPA 结合活性。讨论了分馏 PEG 沉淀后 NPA 结合呈双峰分布的可能解释。
