The Role of Binding Energy in Catalysis: the Work of William P. Jencks

Two Functional Domains of Coenzyme A Activate Catalysis by Coenzyme A Transferase. Pantetheine and Adenosine 3′-Phosphate 5′-Diphosphate (Fierke, C. A., and Jencks, W. P. (1986) J. Biol. Chem. 261, 7603–7606)William Platt Jencks (1927–2007) was born in Bar Harbor, Maine. He became interested in chemistry when he received a chemistry set for Christmas in 1934. He immediately carried out one of the experiments described in the instructions, the addition of dilute acid to a sulfide salt to produce H₂S. The experiment was so successful that his house had to be evacuated due to the smell of rotten eggs. According to Jencks, “My family and I did not find it necessary to replicate this experiment” (1).Open in a separate windowWilliam P. JencksJencks enrolled at Harvard College, intending to study chemistry. However, after taking a first year course in chemistry that “described a large number of chemical reactions, one after the other, with no indication of what was interesting about any of them” (1), he switched his major to English. Despite this change in the direction of his studies, Jencks ended up entering Harvard Medical School after his junior year because he wasn''t sure what else to do.After completing his first year of medical school, Jencks spent a summer at the Marine Biological Laboratory in Woods Hole, taking courses and doing research on lobster shell pigments with Journal of Biological Chemistry (JBC) Classic author George Wald (2). He received his M.D. in 1951 and then interned at Peter Bent Brigham Hospital in Boston. However, after a while, Jencks found medicine to be “a very broad field in which it would be difficult to obtain definitive answers to fundamental problems” (1). Wald suggested Jencks try doing research at Massachusetts General Hospital with Nobel laureate Fritz Lipmann (who was featured in a previous JBC Classic (3)). Jencks ended up spending 2 years with Lipmann, studying coenzyme A transferase, which led to his longtime interest in the physical organic chemistry of acyl transfer reactions. After leaving Massachusetts General Hospital, Jencks spent a year doing postdoctoral studies at Harvard University with Nobel laureate Robert Woodward before joining the faculty at Brandeis University in 1957, serving as assistant, associate, and then full professor of biochemistry. He retired in 1996 as professor emeritus of biochemistry.During his 39 years at Brandeis University, Jencks studied the mechanisms by which enzymes facilitate chemical reactions of molecules that are not otherwise inclined to react at a useful rate.The JBC Classic reprinted here looks at the noncovalent interactions between succinyl-CoA 3-ketoacid coenzyme A transferase and coenzyme A. In the paper, Jencks and Carol A. Fierke used a small coenzyme A analog, methylmercaptopropionate, to show that noncovalent interactions between the enzyme and the side chain of CoA are responsible for the reaction rate increase brought about by the enzyme. They report that interaction between the enzyme and the pantetheine moiety of CoA provides the majority of substrate destabilization and rate acceleration, whereas the interaction with the 3′-phospho-ADP1 moiety provides binding energy that overcomes this destabilization and permits significant binding of acyl-CoA substrates to the enzyme. This paper helped to illuminate a striking example of the role of binding energy in catalysis.Jencks received many honors and awards for his contributions to science, including memberships in the National Academy of Sciences (1971) and the American Philosophical Society (1995) and foreign membership in the Royal Society. He also received the 1962 American Chemical Society (ACS) Award in Biological Chemistry, the 1993 American Society of Biological Chemists Award, the 1995 ACS James Flack Norris Award in Physical Organic Chemistry, and the 1996 ACS Repligen Award for Chemistry of Biological Processes.¹     

Similar Ca(2+)-signaling properties in keratinocytes and in COS-1 cells overexpressing the secretory-pathway Ca(2+)-ATPase SPCA1

Mutations in the ubiquitously expressed secretory-pathway Ca(2+)-ATPase (SPCA1) Ca(2+) pump result in Hailey-Hailey disease, which almost exclusively affects the epidermal part of the skin. We have studied Ca(2+) signaling in human keratinocytes by measuring the free Ca(2+) concentration in the cytoplasm and in the lumen of both the Golgi apparatus and the endoplasmic reticulum. These signals were compared with those recorded in SPCA1-overexpressing and control COS-1 cells. Both the sarco(endo)plasmic-reticulum Ca(2+)-ATPase (SERCA) and SPCA1 can mediate Ca(2+) uptake into the Golgi stacks. Our results indicate that keratinocytes mainly used the SPCA1 Ca(2+) pump to load the Golgi complex with Ca(2+) whereas the SERCA Ca(2+) pump was mainly used in control COS-1 cells. Cytosolic Ca(2+) signals in keratinocytes induced by extracellular ATP or capacitative Ca(2+) entry were characterized by an unusually long latency reflecting extra Ca(2+) buffering by an SPCA1-containing Ca(2+) store, similarly as in SPCA1-overexpressing COS-1 cells. Removal of extracellular Ca(2+) elicited spontaneous cytosolic Ca(2+) transients in keratinocytes, similarly as in SPCA1-overexpressing COS-1 cells. With respect to Ca(2+) signaling keratinocytes and SPCA1-overexpressing COS-1 cells therefore behaved similarly but differed from control COS-1 cells. The relatively large contribution of the SPCA1 pumps for loading the Golgi stores with Ca(2+) in keratinocytes may, at least partially, explain why mutations in the SPCA1 gene preferentially affect the skin in Hailey-Hailey patients.     

Determination of free and amidated bile acids by high-performance liquid chromatography with evaporative light-scattering mass detection.

A simple reverse phase high-performance liquid chromatographic method for a simultaneous analysis of free, glycine- and taurine-amidated bile acids is described. The resolution of ursodeoxycholic, cholic, chenodeocycholic, deoxycholic, and lithocholic acids, either free or amidated with glycine and taurine, is achieved using a C-18 octadecylsilane column (30 cm length, 4 micron particle size) with a gradient elution of aqueous methanol (65----75%) containing 15 mM ammonium acetate, pH 5.40, at 37 degrees C. The separated bile acids are detected with a new evaporative light-scattering mass detector and by absorbance at 200 nm. A complete resolution of the 16 bile acids, including the internal standard nor-deoxycholic acid, is obtained within 55 min. Using the light-scattering mass detector, amidated bile acids and, for the first time, free bile acids can be detected with similar detection limits in the order of 2-7 nmol. The new detector improves the baseline and the signal-to-noise ratio over the UV detection as it is not affected by impurities present in the samples with higher molar absorptivity than bile acids or by the change in the mobile phase composition during the gradient. The method fulfills all the standard requirements of precision and accuracy and the linearity of the mass detector is over 5 decade the detection limit. The new method has been used for the direct analysis of bile acid in stools and bile with only a preliminary clean-up procedure using a C-18 reverse phase extraction.     

In vitro membrane association of the F0 polypeptides of the Escherichia coli proton translocating ATPase.

The F0 polypeptides a, b, and c of the H+-translocating ATPase associated with membranes when synthesized in vitro. This association occurred when the membranes were present either cotranslationally or post-translationally. In addition, the F0 polypeptides associated with liposomes. The membrane association seemed to be an insertion process since there was protection of polypeptides a and c from proteolysis. The in vitro insertion of the F0 polypeptides a, b, and c was independent of the synthesis of each polypeptide and of the F1 polypeptides.     

Immunohistochemistry, histopathology and ultrastructure of Gasterosteus aculeatus tissues infected with Glugea anomala

Immunohistochemical and histopathological studies were conducted on a population of 3-spined sticklebacks Gasterosteus aculeatus (L.) from Loch Airthrey (Stirling, Scotland) naturally infected with the microsporean Glugea anomala (Moniez 1887). Of the 55 host specimens that were examined, 16 (29.09%) were infected, the intensity of infection ranging from 1 to 4 xenomas per fish, which were principally located within the central portion of the body lateral flank musculature. All 32 G. anomala xenomas examined were mature, their diameter ranging from 936 to 2232 Pum, and their walls of presented a laminar structure. Subcutaneously situated xenomas protruded from the fish body surface, whilst xenomas encountered within the intestine were seen to cause distortion. Light and electron microscopical observations confirmed a host cellular reaction around the xenoma, seen by the presence of eosinophile granule cells (EGCs), and some neutrophils. The occurrences of rodlet cells among the intestinal epithelial cells, and in close proximity to the xenoma wall, were observed in certain specimens. Outside the xenoma wall, macrophage aggregates (MAs) were commonly encountered. Within the xenoma wall, the presence of eosinophile granular cells immunoreactive to the anti-serotonin serum was also recorded. Further immunohistochemical tests revealed that a high number of nerve fibres running along the white lateral muscle fibres were immunoreactive to bombesin-, galanin-, and leu-enkephalin-antisera. Nerve fibres containing bombesin- and leu-enkephalin-like substances were also observed in the connective inflammatory tissue around the protozoan cyst, while neurons in the spinal ganglia were immunoreactive to met-enkephalin, and serotonin antisera. The control for the specificity of immunohistochemical reactions was performed using preabsorption tests of each antiserum with the corresponding antigen, and no immunoreactivity was noticed. The data presented are discussed in relation to the occurrence of G. anomala, which alters the pattern of nerve fibres present in the host. Specifically, the protozoan induces a response in the stickleback nervous system, the reaction of which is revealed through the application of immunohistochemical techniques.     

Gene expression profiling of mouse Sertoli cell lines

The proliferation and differentiation of Sertoli cells is regulated by follicle-stimulating hormone (FSH). The molecular events following FSH stimulation are only partially known. To investigate FSH action in Sertoli cells, we established two novel FSH-responsive mouse Sertoli-cell-derived lines expressing human wild-type (WT) FSH receptor (FSHR) or overexpressing mutated (Asp567Gly) constitutively active FSHR (MUT). Gene expression profiling with commercially available cDNA arrays, including 588 mouse genes, revealed 146 genes expressed in both cell lines. Compared with the expression pattern of WT cells, 20 genes were identified as being either up- or down-regulated (>two-fold) in the MUT cells. We observed a strong differential expression of factors involved in cellular proliferation, e.g. cyclin D2 (repressed to nearly undetectable levels), proliferating cell nuclear antigen (2.5-fold repression) and Eps-8 (six-fold repression), and in genes involved in cellular differentiation, e.g. cytokeratin-18 (13-fold induction). The cDNA array results for six representative genes were confirmed by Northern blotting, which also included the parental SK-11 cell line devoid of FSHR expression. We found no further acute FSH- or forskolin-induced change in expression levels after 3-h stimulations, suggesting that the observed differences between the two cell lines is a consequence of mild, chronically increased, cAMP production in MUT cells. These results provide a platform for the further investigation of selected candidate genes in primary cultures and/or in vivo.Electronic Supplementary Material Supplementary material is available in the online version of this article at This work was supported by grants from the Deutsche Forschungsgemeinschaft (Confocal Research Group The Male Gamete: Production, Maturation, Function, grant FOR 197-3) and from the German Academic Exchange Service (DAAD) to P. Mathur