A short, strong hydrogen bond in the active site of human carbonic anhydrase II.

The crystal structure of human carbonic anhydrase II (HCA II) obtained at 0.9 A resolution reveals that a water molecule, termed deep water, Dw, and bound in a hydrophobic pocket of the active site forms a short, strong hydrogen bond with the zinc-bound solvent molecule, a conclusion based on the observed oxygen-oxygen distance of 2.45 A.

Growth and density-dependent regulation of NO synthase by the actin cytoskeleton in pulmonary artery endothelial cells.

We previously reported association of eNOS with actin increases eNOS activity. In the present study, regulation of activity of eNOS by actin cytoskeleton during endothelial growth was studied. We found eNOS activity in PAEC increased when cells grew from preconfluence to confluence.

Conflicting approaches: operant psychology arrives at a primate laboratory.

During a brief period, from 1955 to 1957, behavior analysts, primarily Charles Ferster, Roger Kelleher, and John Falk, conducted research on chimpanzees at the Yerkes Laboratories of Primate Biology in Orange Park, Florida. This was a time of conflict between operant conditioners and more traditional experimental psychologists at the national level, and there was a similar conflict at the local level in Orange Park. The principal overt issues concerned the use of deprivation procedures, the apparatus utilized, and the naming of animals, although more fundamental differences probably set the occasion for the disputes.