The fungal metabolite fumagillin suppresses the formation of new blood vessels, and a fumagillin analog is currently in clinical trials as an anticancer agent. The molecular target of fumagillin is methionine aminopeptidase-2 (MetAP-2). A 1.8 A resolution crystal structure of free and inhibited human MetAP-2 shows a covalent bond formed between a reactive epoxide of fumagillin and histidine-231 in the active site of MetAP-2. Extensive hydrophobic and water-mediated polar interactions with other parts of fumagillin provide additional affinity. Fumagillin-based drugs inhibit MetAP-2 but not MetAP-1, and the three-dimensional structure also indicates the likely determinants of this specificity. The structural basis for fumagillin's potency and specificity forms the starting point for structure-based drug design.

Mutations in palmitoyl-protein thioesterase 1 (PPT1), a lysosomal enzyme that removes fatty acyl groups from cysteine residues in modified proteins, cause the fatal inherited neurodegenerative disorder infantile neuronal ceroid lipofuscinosis. The accumulation of undigested substrates leads to the formation of neuronal storage bodies that are associated with the clinical symptoms. Less severe forms of PPT1 deficiency have been found recently that are caused by a distinct set of PPT1 mutations, some of which retain a small amount of thioesterase activity. We have determined the crystal structure of PPT1 with and without bound palmitate by using multiwavelength anomalous diffraction phasing. The structure reveals an ␣͞␤-hydrolase fold with a catalytic triad composed of Ser115-His289-Asp233 and provides insights into the structural basis for the phenotypes associated with PPT1 mutations.

The effect of temperature and O2 saturation on the production of recombinant proteins beta-galactosidase and human glucocerebrosidase by Spodoptera frugiperda cells (Sf9) infected with recombinant Autographa californica nuclear polyhedrosis virus was investigated. The rates of cell growth, glucose consumption, O2 consumption and product expression were measured at temperatures between 22 degrees C and 35 degrees C. The results indicated that possible O2 limitation may be alleviated without compromising the maximum cell yield by lowering the incubation temperature from 27 degrees C to 25 degrees C. The expression level of the recombinant proteins at 27 degrees C was similar to that obtained at 22 degrees C and 25 degrees C; lower protein yields were obtained at 30 degrees C. An increase in temperature from 22 degrees C to 27 degrees C led to earlier production of the proteins and to an increase in the proportion of the product released outside the cells.

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