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Obesity is a chronic, costly, and globally prevalent condition, with excess caloric intake a suspected etiologic factor. Nonsurgical treatments are modestly efficacious, and weight loss maintenance is hampered by anti-famine homeostatic mechanisms. Ghrelin, a gastric hormone linked to meal initiation, energy expenditure, and fuel partitioning, is hypothesized to facilitate weight gain and impede weight loss. Unique among known animal peptides, the serine-3 residue of ghrelin is posttranslationally acylated with an n-octanoic acid, a modification important for the peptide's active blood-brain transport and growth hormone secretagogue receptor-1 agonist activity. Pharmacological degradation of ghrelin would be hypothesized to reduce ghrelin's biological effects. To study endogenous ghrelin's role in appetite and energy expenditure, we generated antibodies that hydrolyze the octanoyl moiety of ghrelin to form des-acyl ghrelin. The most proficient antibody catalyst, GHR-11E11, was found to display a second-order rate constant of 18 [M.sup.-] 1 x [s.sup.-1] for the hydrolysis of ghrelin to des-acyl ghrelin. l.v. administration of GHR-11E11 (50 mg/kg) maintained a greater metabolic rate in fasting C57BL/6J mice as compared with mice receiving a control antibody and suppressed 6-h refeeding after 24 h of food deprivation. Indirect respiratory measures of metabolism after refeeding and relative fuel substrate utilization were unaffected. The results support the hypothesis that acylated ghrelin stimulates appetite and curbs energy expenditure during deficient energy intake, whereas des-acyl ghrelin does not potently share these functions. Catalytic anti-ghrelin antibodies might thereby adjunctively aid consolidation of caloric restriction-induced weight loss and might also be therapeutically relevant to Prader-Willi syndrome, characterized after infancy by hyperghrelinemia, hyperphagia, and obesity. hormone inactivation | obesity | neuropeptides

Obesity endangers the lives of millions of people worldwide, through comorbidities such as heart disease, cancers, type 2 diabetes, stroke, arthritis, and major depression. New approaches to control body weight remain a high priority. Vaccines traditionally have been used to protect against infectious diseases and, more recently, for unconventional targets such as drug addiction. Methodologies that could specifically modulate the bioavailability of an endogenous molecule that regulates energy balance might provide a new foundation for treating obesity. Here we show that active vaccination of mature rats with ghrelin immunoconjugates decreases feed efficiency, relative adiposity, and body weight gain in relation to the immune response elicited against ghrelin in its active, acylated form. Three active vaccines based on the 28-aa residue sequence of ghrelin, a gastric endocrine hormone, were used to immunize adult male Wistar rats (n = 17). Synthetic ghrelin analogs were prepared that spanned residues 1-10 [ghrelin (1-10) Ser-3(butanoyl) hapten, Ghrl], 13-28 [ghrelin (13-28) hapten, Ghr2], and 1-28 [ghrelin(1-28) Ser-3(butanoyl) hapten, Ghr3], and included n-butanoyl esters at Ser-3. Groups immunized with Ghr1 or Ghr3 showed greater and more selective plasma binding capacity for the active, Ser-3-(n-octanoyl) form of ghrelin as compared with Ghr2 or keyhole limpet hemocyanin vaccinated controls. Accordingly, they gained less body weight, with sparing of lean mass and preferential reduction of body fat, consistent with reduced circulating leptin levels. The ratio of brain/serum ghrelin levels was lower in rats with strong anti-ghrelin immune responses. Effects were not attributable to nonspecific inflammatory responses. Vaccination against the endogenous hormone ghrelin can slow weight gain in rats by decreasing feed efficiency. feed efficiency | ghrelin | obesity | body weight regulation | vaccine

The synthesis of a series of cocaine-fluorophore conjugates and the functional evaluation of the compounds against single-chain Fv antibodies are described. It was determined that the GNC-F2 fluorophore reproduced affinity constants obtained using [(super 3)H]-labeled cocaine.

Bacteria use small diffusible molecules to exchange information in a process called quorum sensing. An important class of autoinducers used by Gram-negative bacteria is the family of N-acylhomoserine lactones. Here, we report the discovery of a previously undescribed nonenzymatically formed product from N-(3-oxododecanoyl)-L-homoserine lactone; both the N-acylhomoserine and its novel tetramic acid degradation product, 3-(1-hydroxydecylidene)-5-(2-hydroxyethyl) pyrrolidine-2,4-dione, are potent antibacterial agents. Bactericidal activity was observed against all tested Gram-positive bacterial strains, whereas no toxicity was seen against Gram-negative bacteria. We propose that Pseudomonas aeruginosa utilizes this tetramic acid as an interference strategy to preclude encroachment by competing bacteria. Additionally, we have discovered that this tetramic acid binds iron with comparable affinity to known bacterial siderophores, possibly providing an unrecognized mechanism for iron solubilization. These findings merit new attention such that other previously identified autoinducers be reevaluated for additional biological functions. tetramic acid | bactericidal agents | evolution

Study aimed at determining the origin and thus the mechanism of the nornicotine-catalyzed aqueous aldol reaction is reported. Computational studies revealed that both the catalyzed and uncatalyzed reactions appear to proceed through a two-step mechanism in water in which a stable intermediate is generated.

Cocaine addiction continues to be a major health and social problem in the United States and other countries. Currently used pharmacological agents for treating cocaine abuse have proved inadequate, leaving few treatment options. An alternative is to use protein-based therapeutics that can eliminate the load of cocaine, thereby attenuating its effects. This approach is especially attractive because the therapeutic agents exert no pharmacodynamic action of their own and therefore have little potential for side effects. The effectiveness of these agents, however, is limited by their inability to act directly within the CNS. Bacteriophage have the capacity to penetrate the CNS when administered intranasally. Here, a method is presented for engineering filamentous bacteriophage to display cocaine-binding proteins on its surface that sequester cocaine in the brain. These antibody-displaying constructs were examined by using a locomotor activity rodent model to assess the ability of the phage-displayed proteins to block the psychoactive effects of cocaine. Results presented demonstrate a strategy in the continuing efforts to find effective treatments for cocaine addiction and suggest the application of this protein-based treatment for other drug abuse syndromes.

A comprehensive study of the expanded spectrum of [C.sub.12]-TA antibacterial activity against microbial competitors encountered by Pseudomonas aeruginosa in nature as well as significant human pathogens is presented. The obtained results provide insight into the evolved QS machinery of P. aeruginosa for a dual-function which involve both to signal others of the same species and also to defend against host immunity and competing bacteria.

The 'quorum sensing' mechanism in Pseudomonas aeruginosa was targeted with a set of electrophilic probes designed to covalently bind Cys79 in the LasR binding pocket which lead to specific inhibition of QS-regulated gene expression concomitant reduction of virulence factor secretion and biofilm formation. The newly modified covalent QS receptor provides a new tool to study molecular mechanisms of bacterial group behavior and could lead to new strategies for targeting bacterial virulence.

An enzyme-based biofuel cell with a pH-switchable oxygen electrode is developed, which is controlled by enzyme logic operations processing in situ biochemical input signals. The study has shown a switchable bioelectrode for bioelectrocatalytic reduction of oxygen and its integration into a biofuel cell resulting in the release of power controlled by multiple biochemical signals processed with Boolean logic.

The stability of several N-acyl L-homoserine lactones (AHLs) is investigated under physiological conditions to guide the hapten design and a number of AHL analogues and their corresponding ring-opened hydrolysis products are synthesized. It was found that RS2IG9 possessed the ability to inhibit 3-oxo-C12-AHL-based quorum sensing (QS) signaling and it might be used as a tool for investigating 3-oxo-C12-AHL-based QS.

Several studies conducted indicate that every year smoking and chewing tobacco, account for more than 500 000 deaths in the United States alone. Evidence indicates that people continue to smoke and use tobacco due to the addictive effects of nicotine.

The cleavage of the phosphodiester backbone of DNA by (1,10-phenanthroline)copper was carried out under aerobic and anaerobic conditions to determine the source of the carbonyl oxygen atom of 5-methylenefuranone (5-MF). The latter, together with free base and phosphorylated ends, are major products of the DNA scission reaction. Using poly dA-T as the substrate and 3-mercaptopropionic acid as the activation agent, the oxygen of water was found to be the atom source of the carbonyl oxygen of 5-MF.