Eleven N-peptidyl-O-aroyl hydroxylamines have been synthesized and their hydrolytic stability, acidity and properties during reaction with dipeptidyl peptidase IV (E.C. 3.4.14.5) investigated. N-peptidyl-O-(4-nitrobenzoyl) hydroxylamines act as irreversible inhibitors of serine proteases. The serine enzyme, dipeptidyl peptidase IV (DP IV), is inactivated by substrate analog derivatives of this class by a suicide inactivation mechanism. During the enzyme reaction of DP IV with the suicide substrates most molecules are hydrolyzed but some irreversibly inactivate the target enzyme. In contrast to porcine pancreatic elastase and thermitase, DP IV exhibits a high ratio for hydrolysis of the compounds versus inhibition during their interaction with the enzyme. Variation of the leaving aroyl residue lowers this ratio. Variation of the substrate analog peptide moieties of the DP IV-inhibitors increases their ability to inhibit the enzyme to a remarkable extent. Possible reaction pathways are discussed.

Background Anesthesia and sleep share physiological and behavioral similarities. The anesthetic requirement of the recently identified Drosophila mutant minisleeper and other Drosophila mutants was investigated. Methods Sleep and wakefulness were determined by measuring activity of individual wild-type and mutant flies. Based on the response of the flies at different concentrations of the volatile anesthetics isoflurane and sevoflurane, concentration-response curves were generated and EC50 values were calculated. Results The average amount of daily sleep in wild-type Drosophila (n=64) was 965 ±15 minutes and 1022 ± 29 in na[har38] p>0.05; n=32) (mean ± SEM, all p compared to wild-type and other shaker alleles). Shmns flies slept 584 ±13 minutes (n=64, p<0.01), Sh102 412 ± 22 minutes (n=32, p<0.01) and Sh120 782 ± 25 minutes (n=32, p<0.01). The EC50 values for isoflurane were 0.706 (95% confidence interval 0.649 to 0.764, n=661) and for sevoflurane 1.298 (1.180 to 1.416, n=522) in wild-type Drosophila, 1.599 (1.527 to 1.671, n=308) and 2.329 (2.177 to 2.482, n=282) in Sh102, 1.306 (1.212 to 1.400, n=393) and 2.013 (1.868 to 2.158, n=550) in Shmns, 0.957 (0.860 to 1.054, n=297) and 1.619 (1.508 to 1.731, n=386) in Sh120, and 0.6154 (0.581 to 0.649, n=360; p<0.05) and 0.9339 (0.823 to 1.041, n= 274) in na[har38], respectively (all p<0.01). Conclusions A single-gene mutation in Drosophila that causes an extreme reduction in daily sleep is responsible for a significant increase in the requirement of volatile anesthetics. This suggests that a single gene mutation affects both sleep behavior and anesthesia and sedation.

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