Three weeks on the West River of Canton.

Mode of access: Internet.

"My love!"

Mode of access: Internet.

American art and American art collections; essays on artistic subjects by the best art writers, fully illustrated with etchings, photo-etchings, photogravures, phototypes, and engravings on steel and wood, by the most celebrated artists;

"Linton's History of wood engraving in America": v.1, p. 401-528.

Life of William Blake, "Pictor ignotus". With selections from his poems and other writings,

Preface signed: Anne Gilchrist.

Plays /

"Reproduced by Duopage process."

Effects of diverting sediment-laden runoff from arroyos to range and crop lands /

Mode of access: Internet.

The life of paine.

Mode of access: Internet.

The life of Paine.

Mode of access: Internet.

Modern slavery

Master microform held by: DLC.

The scenery of Greece and its islands, illustrated by fifty views, sketched from nature, executed on steel, and described en route, with a map of the country.

Mode of access: Internet.

The autobiography of Christoper Kirkland.

A novel.

Principles of the law of contract, with a chapter on the law of agency,

Mode of access: Internet.

Annals of archaeology and anthropology.

At head of title: University of Liverpool.

Review

WHEN MEDIA ARE NEW: UNDERSTANDING THE DYNAMICS OF NEW MEDIA ADOPTION AND USE, JOHN CAREY AND MARTIN C. J. ELTON (2010) Ann Arbor, MI: University of Michigan Press (374 pp.), ISBN 978-0-472-05085-7, $47.50 (paperback). YOU ARE NOT A GADGET: A MANIFESTO, JARON LANIER (2011) New York: Vintage (240 pp.), ISBN 978-0307389978, $15 (paperback) EXTRAORDINARY CANADIANS: MARSHALL McLUHAN, DOUGLAS COUPLAND (2010) Toronto, Canada: Penguin Canada (208 pp.), ISBN 9780670069224, $26 (hardback)

The topography of transmembrane segment six is altered during the catalytic cycle of P-glycoprotein

Structural evidence has demonstrated that P-glycoprotein (P-gp) undergoes considerable conformational changes during catalysis, and these alterations are important in drug interaction. Knowledge of which regions in P-gp undergo conformational alterations will provide vital information to elucidate the locations of drug binding sites and the mechanism of coupling. A number of investigations have implicated transmembrane segment six (TM6) in drug-P-gp interactions, and a cysteine-scanning mutagenesis approach was directed to this segment. Introduction of cysteine residues into TM6 did not disturb basal or drug-stimulated ATPase activity per se. Under basal conditions the hydrophobic probe coumarin maleimide readily labeled all introduced cysteine residues, whereas the hydrophilic fluorescein maleimide only labeled residue Cys-343. The amphiphilic BODIPY-maleimide displayed a more complex labeling profile. The extent of labeling with coumarin maleimide did not vary during the catalytic cycle, whereas fluorescein maleimide labeling of F343C was lost after nucleotide binding or hydrolysis. BODIPY-maleimide labeling was markedly altered during the catalytic cycle and indicated that the adenosine 5'-(beta,gamma-imino)triphosphate-bound and ADP/vanadate-trapped intermediates were conformationally distinct. Our data are reconciled with a recent atomic scale model of P-gp and are consistent with a tilting of TM6 in response to nucleotide binding and ATP hydrolysis.