Department of Plant Biology, University of Minnesota, 1445 Gortner Avenue, 55108-1095, St. Paul, MN, USA.
Photosynth Res. 1993 Feb;35(2):103-16. doi: 10.1007/BF00014742.
About 1939, Sam Ruben and Martin Kamen introduced me to the emergent application of artificial radio-isotopes in the study of photosynthesis. While my own experiments on CO2 fixation by isolated chloroplasts turned out to be negative, their laboratory provided me with an informative and exciting experience. Also, there were many stimulating contacts with Cornelis van Niel, Robert Emerson, Don DeVault and many other outstanding scientists. Efforts on my part to obtain a better understanding of intermediary metabolism, eventually led me to Fritz Lipmann's laboratory. There I was encouraged to study the metabolic activities of cell-free preparations of photosynthetic purple bacteria. Investigations of oxidative phosphorylation by isolated bacterial chromatophores in the dark raised questions about the possible effects of light on the phosphorylation activities of such preparations. Surprisingly, high rates of phosphorylation were observed in the light in the absence of molecular oxygen ('light-induced phosphorylation'). In this process, adenosine diphosphate (ADP) and inorganic phosphate (Pi) could be converted quantitatively into adenosine triphosphate (ATP). It was postulated that this process was 'cyclic' in nature, as only catalytic concentrations of added electron donors were required. Later, at Minnesota, it could be shown that similar chromatophore preparations, in the presence of suitable electron donors, could reduce nicotinamide-adenine dinucleotide (NAD(+)) to NADH in the light. It was then demonstrated that the chromatophores of Rhodospirilum rubrum, as well as the smaller membrane components derived from them, must contain the active metabolic components for these photosynthetic reactions.These observations, and studies on the kinetics of the formation and decay of light-induced free radicals, appeared to demonstrate the usefulness of bacterial chromatophores and of their membrane fragments in the study of partial reactions of bacterial photosynthesis. Since that time, numerous investigators elsewhere have carried out remarkable research on the purification and eventual crystallization of distinct bacterial membrane components, capable of carrying out well characterized photochemical and electron transport reactions.
大约在 1939 年，山姆·鲁本（Sam Ruben）和马丁·卡门（Martin Kamen）让我接触到人工放射性同位素在光合作用研究中的新兴应用。虽然我自己关于离体叶绿体固定二氧化碳的实验结果是否定的，但他们的实验室为我提供了丰富而令人兴奋的经验。此外，我还与科内利斯·范尼尔（Cornelis van Niel）、罗伯特·爱默生（Robert Emerson）、唐·德沃尔夫（Don DeVault）和许多其他杰出的科学家进行了多次富有启发性的交流。我努力更好地了解中间代谢，最终导致我进入弗里茨·李普曼（Fritz Lipmann）的实验室。在那里，我被鼓励研究光合紫色细菌无细胞制剂的代谢活性。在黑暗中对分离的细菌类囊体进行氧化磷酸化的研究提出了关于光照对这些制剂磷酸化活性可能产生的影响的问题。令人惊讶的是，在没有分子氧的情况下（“光诱导磷酸化”），在光下观察到高磷酸化率。在这个过程中，二磷酸腺苷（ADP）和无机磷酸（Pi）可以定量转化为三磷酸腺苷（ATP）。有人假设这个过程本质上是“循环”的，因为只需要催化浓度的外加电子供体。后来，在明尼苏达州，人们可以证明，在适当的电子供体存在下，类似的类囊体制剂可以在光照下将烟酰胺腺嘌呤二核苷酸（NAD(+)）还原为 NADH。然后证明，红螺菌（Rhodospirilum rubrum）的类囊体以及从它们衍生的较小的膜成分，必须包含这些光合作用反应的活性代谢成分。这些观察结果以及对光诱导自由基形成和衰减动力学的研究似乎表明，细菌类囊体及其膜片段在细菌光合作用部分反应的研究中是有用的。从那时起，其他地方的许多研究人员对独特的细菌膜成分的纯化和最终结晶进行了卓越的研究，这些成分能够进行特征明确的光化学和电子传递反应。
