Metal-Directed Design of Supramolecular Protein Assemblies.

Owing to their central roles in cellular signaling, construction, and biochemistry, protein-protein interactions (PPIs) and protein self-assembly have become a major focus of molecular design and synthetic biology. In order to circumvent the complexity of constructing extensive noncovalent interfaces, which are typically involved in natural PPIs and protein self-assembly, we have developed two design strategies, metal-directed protein self-assembly (MDPSA) and metal-templated interface redesign (MeTIR). These strategies, inspired by both the proposed evolutionary roles of metals and their prevalence in natural PPIs, take advantage of the favorable properties of metal coordination (bonding strength, directionality, and reversibility) to guide protein self-assembly with minimal design and engineering. Using a small, monomeric protein (cytochrome cb562) as a model building block, we employed MDPSA and MeTIR to create a diverse array of functional supramolecular architectures which range from structurally tunable oligomers to metalloprotein complexes that can properly self-assemble in living cells into novel metalloenzymes. The design principles and strategies outlined herein should be readily applicable to other protein systems with the goal of creating new PPIs and protein assemblies with structures and functions not yet produced by natural evolution.

Differentiation of the sibling species Biomphalaria occidentalis and Biomphalaria tenagophila by the electrophoretic patterns of their hemoglobin.

A simple and rapid method for differentiating the sibling species Biomphalaria tenagophila and Biomphalaria occidentalis by agarose gel electrophoresis (AGE) is described. Snail hemolymph is used as the test sample and the red coloration of the hemoglobin fraction permits visualization of the migration patterns without resorting to specific stains. Moreover, hemolymph samples may be obtained without killing the snail, thus permitting its use for other studies or for breeding.

Sabulodes caberata guenée (Lepidoptera: Geometridae) : Components of its sex pheromone gland.

A 6,9-nonadecadiene, (Z)-9-nonadecene, andn-nonadecane were identified in extracts of sex pheromone glands of femaleSabulodes caberata Guenée. Potential pheromonal activity of gland components was assessed by electroantennogram measurements of gas-chromatographic fractions of abdominal tip extracts. Chemical identification was based on gas chromatography and mass spectrometry of parent compounds, hydrogenation products, ozonolysis products, dimethyl disulfide adducts, and synthesis. The monoene was synthesized via coupling of alkyl and acetylenic intermediates. (Z,Z)-6,9-Nonadecadiene (Z6,Z9-19∶H) was synthesized from methyl linoleate via chain lengthening. SyntheticZ6,Z9-19∶H had the same retention times on polar and nonpolar capillary gas-chromatographic columns as the 6,9-nonadecadiene from the sex pheromone glands. In field testsZ6,Z9-19:H alone produced trap catch of maleS. caberata and addition of (Z)-9-nonadecene orn-nonadecane had no effect on trap catch.

Western avocado leafroller,Amorbia cuneana (Walsingham), (Lepidoptera: Tortricidae) : Discovery of populations utilizing different ratios of sex pheromone components.

The most effective lure for maleAmorbia cuneana (Walsingham) in Orange, Ventura, and Riverside counties of California was previously found to be a 1∶1 ratio of (E,E)-10,12- and (E,Z)-10,12-tetradecadien-1-ol acetates. In subsequent field tests in San Diego and Santa Barbara counties, this lure was ineffective. Analysis of sex pheromone glands (SPG) of femaleA. cuneana from these two counties showed theEE:EZ ratio to be about 1∶9 and synthetic lures of this composition were highly attractive in these areas. Analysis of the SPG of a number of females from both areas showed that there were three population types: two in the low ratio areas possessed 37 and 58%EZ, and the third in the high ratio areas possessed 89%EZ.

Sex pheromone of the avocado pest,Amorbia cuneana (Walsingham) (Lepidoptera: Tortricidae) : Structure and synthesis.

The major volatile components in the extract of the female sex pheromone gland ofAmorbia cuneana consisted of (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetates. The identification was based on electroantennogram bioassay of gas Chromatographic effluent from sex pheromone gland extract, relative retention times on polar and nonpolar gas chromatographic columns, chemical degradation (ozonolysis, saponification), mass spectrometry, chemical synthetic methods, and field tests. Based on mass spectrometry and retention times by capillary gas chromatography, traces of (E)-10-tetradecen-1-ol acetate and 1-tetradecanol acetate were also present in the extract. Traps baited with a combination of synthetic (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetates caught more males than did traps baited with females.

Degradation of parathion applied to peach leaves.

Parathion was applied to peach trees in three different formulations 70 days before harvest. Leaf samples were taken periodically through the 70-day period and gas-liquid chromatographic analyses were conducted for dislodgable and penetrated residues. Analyses were also conducted for paraoxon and the s-ethyl isomer of parathion. Punched samples were compared to whole-leaf samples; generally residue levels for both types corresponded closely. A new experimental formulation, encapsulated parathion, produced highest levels of total parathion throughout the 70-day study, but even this formulation resulted in low total residue levels around 1 ppm at time of harvest. Degradation of the s-ethyl isomer of parathion was generally very rapid in all formulations studied. Dislodgable residues of paraoxon may be significant in some formulations and should be included in parathion degradation studies. Much of the parathion found on peach leaves throughout the growing season was dislodgable residue, but this depended considerably on the formulation used.

Modification of severe disruptive and aggressive behavior using brief timeout and reinforcement procedures.

Brief timeout for disruptive and aggressive behaviors and reinforcement for appropriate behaviors were used with two retarded patients in a state hospital ward setting. The procedures reduced loud vocal behavior in one patient and aggressive behavior in another to near-zero levels when first applied. The behaviors returned to previous levels when the procedures were removed and were again greatly reduced when timeout and reinforcement were reapplied. The results were significant because the behavior problems were severe and long-standing and the procedures were instituted without greatly disturbing normal ward routine.