A Research Journey with ATP Synthase

Abstract

These reflections present a perspective of how I and my graduate students and postdoctoral fellows, over a span of many years, arrived at the concept that ATP is made by an unusual rotational catalysis of the ATP synthase. A recent sketch of the structure of this remarkable enzyme is given in Fig. 1. Such a depiction is the culmination of the efforts of many investigators.1 The two portions of the enzyme are the membrane-imbedded F 0 and the attached F 1 that has three catalytic sites, principally on the large ␤ subunits. ATP is formed when protons pass through the F 0 , driving the rotation of the ring-shaped cluster of c subunits and the attached ⑀ and ␥ subunits. Other subunits attached to outer portions of the F 0 and F 1 served as a stator. The internal rotary movement of the ␥ subunit is coupled to sequential changes in the conformation of the catalytic sites. During ATP synthesis these conformational changes promote the binding of ADP and P i , the formation of tightly bound ATP, and the release of ATP.Revealing the mechanism of the ATP synthase became a major research goal in the latter part of my long career. This paper recalls how my career developed as related to the remarkable progress in biochemical knowledge. It presents the background and results of fruitful, as well as mistaken, approaches that were explored. The Early YearsBorn and educated through college in Utah, at the age of 21 I entered graduate school in the Department of Biochemistry at the University of Wisconsin in the fall of 1939. The biochemical research and teaching there were excellent. Not until years later did I appreciate all that is necessary to create such a fine scientific environment.I had had no previous courses or research experience in biochemistry and was uncertain about my career choice. By the end of my first year of graduate study the fascination of biochemical understanding and the addictive effect of experimental attempts to uncover new knowledge had firmly launched me toward a career in biochemical research. The Department of Biochemistry at Wisconsin was at the forefront of research in nutrition and metabolism. Recent achievements included the identification of nicotinic acid as a vitamin, the irradiation of milk to produce vitamin D, the discovery of a vitamin K antagonist (dicoumarin), and the discovery of lipoic acid as a growth factor for bacteria. At that time incoming graduate students were assigned to a mentor professor. Both Henry Lardy, from South Dakota, and I joined the group of Professor Paul Phillips whose major interest was in dairy cattle nutrition. Evidence had been obtained that vitamin C might help prevent reproductive difficulties in cattle, and one of my assignments was to find if vitamin C might ameliorate the reproductive failure that occurred in rats with vitamin E deficiency. No benefits of vitamin C were noted, but the rats 1 Except for a few instances, the mention of important advances in information about the ATP synthase and in related areas of biochemistry is included without specific ...

Lysosomal accumulation of SCMAS (subunit c of mitochondrial ATP synthase) in neurons of the mouse model of mucopolysaccharidosis III B

“…SCMAS is a small hydrophobic protein that plays a major role in oxidative phosphorylation in mitochondria [13]. Pathologic accumulation of SCMAS is a hallmark of late infantile neuronal ceroid lipofuscinosis (NCL) as well as of the juvenile (Batten's disease) and other forms of NCL.…”

The product of uncI gene in F 1 F o -ATP synthase operon plays a chaperone-like role to assist c -ring assembly

“…is located in membranes of mitochondria and chloroplast thylakoid, and cytoplasmic membranes of bacteria, and it couples ATP synthesis/hydrolysis with transmembrane H ϩ or Na ϩ translocation (1,2). F 1 F o is composed of two domains, water-soluble F 1 that has nucleotidebinding sites for ATP synthesis/hydrolysis, and membraneintegral F o that mediates H ϩ translocation across the membrane.…”

A second generation synthesis of the cruentaren A core structure based on oxetane and oxirane opening reactions

“…After addition of boron trifluoro etherate (2.6 mL, 21 mmol) stirring was continued for 1 h. At this point, oxetane 27 (2.5 g, 11.3 mmol) in dry THF (7 mL) was added and stirring was maintained for 1.5 h at -80 °C. The reaction was quenched by the addition of saturated NH 4 Cl solution, and the mixture extracted thrice with diethyl ether. The combined organic layers were washed with saturated NaHCO 3 …”

“…3 This group of enzymes enables fundamental cellular events such as the synthesis of ATP or transport processes that consume ATP. 4 The vacuolar ATPase (V-ATPase), for example, is wide-spread in eukaryotic cells. It functions as a molecular motor and results in the transport of protons against a proton gradient.…”