Our fundamental understanding of proteins and their biological significance has been enhanced by genetic fusion tags, as they provide a convenient method for introducing unique properties to proteins so that they can be examinedin isolation. Commonly used tags satisfy many of the requirements for applications relating to the detection and isolation of proteins from complex samples. However, their utility at low concentration becomes compromised if the binding affinity for a detection or capture reagent is not adequate to produce a stable interaction. Here, we describe HaloTag® (HT7), a genetic fusion tag based on a modified haloalkane dehalogenase designed and engineered to overcome the limitation of affinity tags by forming a high affinity, covalent attachment to a binding ligand. HT7 and its ligand have additional desirable features. The tag is relatively small, monomeric, and structurally compatible with fusion partners, while the ligand is specific, chemically simple, and amenable to modular synthetic design. Taken together, the design features and molecular evolution of HT7 have resulted in a superior alternative to common tags for the overexpression, detection, and isolation of target proteins.

The development of emotional regulation capacities in children at high versus low risk for externalizing disorder was examined in a longitudinal study investigating: (a) whether disturbances in emotion regulation precede and predict the emergence of externalizing symptoms and (b) whether sensitive maternal behavior is a significant influence on the development of child emotion regulation. Families experiencing high (n = 58) and low (n = 63) levels of psychosocial adversity were recruited to the study during pregnancy. Direct observational assessments of child emotion regulation capacities and maternal sensitivity were completed in early infancy, at 12 and 18 months, and at 5 years. Key findings were as follows. First, high-risk children showed poorer emotion regulation capacities than their low-risk counterparts at every stage of assessment. Second, from 12 months onward, emotion regulation capacities showed a degree of stability and were associated with behavioral problems, both concurrently and prospectively. Third, maternal sensitivity was related to child emotion regulation capacities throughout development, with poorer emotion regulation in the high-risk group being associated with lower maternal sensitivity. The results are consistent with a causal role for problems in the regulation of negative emotions in the etiology of externalizing psychopathology and highlight insensitive parenting as a potentially key developmental influence.

The pharynx is a common, asymptomatic reservoir for gonorrhea in sexually active MSM.

Solubility of a model protein, hen egg-white lysozyme, was investigated in a wide range of neat nonaqueous solvents and binary mixtures thereof. All solvents that are protic, very hydrophilic, and polar readily dissolve more than 10 mg/mL of lysozyme (lyophilized from aqueous solution of pH 6.0). Only a marginal correlation was found between the lysozyme solubility in a non-aqueous solvent and the letter's dielectric constant or Hildebrand solubility parameter, and no correlation was observed with the dipole moment. Lysozyme dissolved in dimethyl sulfoxide (DMSO) could be precipitated by adding protein nondissolving co-solvents, although the enzyme had a tendency to form supersaturated solutions in such mixtures. The solubility of lysozyme, both in an individual solvent (1,5-pentanediol) and in binary solvent mixtures (DMSO/acetonitrile), markedly increased when the pH of the enzyme aqueous solution prior to lyophilization was moved away from the proteins's isoelectric point.

Although NS was commonly practiced among HIV-negative men in seroconcordant relationships, some men violated NS-defining rules, placing themselves and potentially their primary partners at risk for HIV infection. Prevention efforts regarding NS should emphasize the importance of agreement adherence, disclosure of rule breaking, and routine STI testing.