Jirsakova Vladimira, Reiss-Husson Françoise, Ranck Jean-Luc
CGM, Bât 24, CNRS, 91198 Gif sur Yrette, France.
Biochim Biophys Acta. 1996 Nov 12;1277(1-2):150-160.
Molecular weights of the purified light-harvesting complexes B800-850 and B875 from purple bacterium Rubrivivax gelatinosus were determined in detergent solutions by analytical centrifugation. The precise density measurement of the antenna solutions provided the values of the buoyant factor of both complexes. Phospholipid content was measured in both antennae. Sedimentation velocity and equilibrium centrifugation indicated that the B800-850 sample is monodisperse and composed from heptamers (α/β/3 Bacteriochlorophyll α 1.3 Carotenoid). B875 is not monodisperse but analysis of equilibrium centrifugation indicated that its smallest oligomer is a dodecamer (α/β/2 BChlα/2 hydroxyspheroidene); larger oligomers probably coexist. The amount of bound detergent could be calculated. B800-850 binds about 0.4-0.5 g of lauryl-dimethyl-amine oxide per g of protein (i.e., 28-35 detergent molecules per α β ) while a large amount of detergent (2.3 g of decanoylsucrose per g of protein, i.e., 64 detergent molecules per α β ) is bound to 13875. The electron microscopy images of both antennae in detergent solutions after negative staining are presented and compared to the centrifugation results.
通过分析离心法测定了来自嗜胶红假单胞菌的纯化捕光复合物B800 - 850和B875在去污剂溶液中的分子量。对天线溶液进行精确的密度测量得出了两种复合物的浮力因子值。测定了两种天线中的磷脂含量。沉降速度和平衡离心表明，B800 - 850样品是单分散的，由七聚体（α/β/3细菌叶绿素α 1.3类胡萝卜素）组成。B875不是单分散的，但平衡离心分析表明其最小的寡聚体是十二聚体（α/β/2 BChlα/2羟基球形烯）；可能共存有更大的寡聚体。可以计算出结合去污剂的量。B800 - 850每克蛋白质结合约0.4 - 0.5克月桂基二甲基氧化胺（即每个αβ结合28 - 35个去污剂分子），而大量的去污剂（每克蛋白质2.3克癸酰蔗糖，即每个αβ结合64个去污剂分子）与B875结合。给出了两种天线在去污剂溶液中负染后的电子显微镜图像，并与离心结果进行了比较。
