Johnson, Louise

Christopher C. Johnson, Louise E. Ander, Robert T. Lister, and Deirdre M. A. Flight ... 

MARGARET A. JOHNSON, KATE M.D. BUSHBY, LOUISE V.B. ANDERSON, and JOHN B. HARRIS... 

The pattern consists of thousands of diffraction spots arranged on intersecting rings. The coordinates of the diffraction spots together with their measured intensities provide the necessary information for structure determination. Courtesy of Louise Johnson. 

This carboxylate blocks access to the P site in the free T-state enzyme. Here, the positively charged Arg 569 guanidinium group has swung in to interact with the P . From Mitchell et al.133 Courtesy of Louise N. Johnson. 

Louise Johnson and her coworkers have determined the crystal structures of T and the R forms of muscle phosphorylase b and the R form of phosphorylase a. In parallel with this work, Robert Fletterick and coworkers determined the structure of the T form of muscle phosphorylase a. The crystal structures provide an incisive look at the structural changes that accompany the transitions from the T to the R conformation and from the nonphosphorylated form of the enzyme to the phosphorylated form. 

The phosphorylated and unphosphorylated forms of glycogen phosphorylase have markedly different conformations, as shown by high-resolution X-ray crystallography, carried out by Louise Johnson and David Barford, in Oxford and by Robert Fletterick and Steven Sprang in San Francisco. The structures provide an explanation for the low activity of the unphosphorylated enzyme b and the high activity of the phosphorylated enzyme a (Plate 14). 

Cover image was generously contributed by Professor Louise N. Johnson, F.R.S., Director of the Laboratory of Molecular Biophysics of the University of Oxford. It shows glycogenphosphory-lase with the N-terminal peptide in the active phosphorylated conformation in comparison with the inactive non-phosphorylated conformation. 

Perez S, Imberty A, Engelsen SB, Gruza J, Mazeau K, Jimenez-Barbero J, Poveda A, Espinosa JE, van Eyck BP, Johnson G, Erench AD, Louise M, Kouwijzer CE, Grootenuis PDJ, Bernardi A, Raimondi L, Senderowitz H, Durier V, Vergoten G, Rasmussen K (1998) Carbohydr Res 314 141... 

Virtually all the work described in this article was performed by an excellent postgraduate student, Miss (now Dr.) Louise J. Gill, whose commitment and enthusiasm remained undimmed throughout three years of hard work. All of the crystal structures were solved by Harry Adams (sometimes assisted by groups of undergraduate students) without whom we would still be completely in the dark about many of our products. We would also like to thank the EPSRC for a studentship and Johnson Matthey pic for a generous loan of ruthenium chloride. 

We express our sincere thanks to Dr. Louise G. Edwards who carried out many of the seminal experiments described in this review. Other important contributions were made by Cathleen M. Cradden, Julia C. Lautens, A. Catherine Smith, Christian Sood, and Marc Johnson. 

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