PMC

One-dimensional case of a buffered EDL with a negatively charged wall (25 °C, 1.5 thermal volts or 38.5 mV), and uniunivalent weak acid buffer (e.g., 40 μM. weak acid, pK_a 5.2, titrated with sodium hydroxide to create a pH 5 buffer). Solid lines denote concentrations of species found in both the weak and strong electrolyte cases (with the same distribution). Shown are analytical concentration of the weak acid family (purple), weak acid (black, HA), conjugate base of weak acid (green, A⁻), Na⁺ ion (orange, Na⁺), and hydroxide ion (blue, H⁺). The hydroxide anion is very low in concentration and not shown for the sake of simplicity. Shown are exact solutions to the Poisson–Boltzmann equation for both strong and weak electrolyte systems. The former is from Hunter, and the latter follows from the current work.

Northern analysis of HSP12 and PDR12 expression during weak acid stress. (A) Cells were grown to the logarithmic growth phase in rich medium and exposed to the indicated weak acids for 20 min. Methylene blue staining of rRNA served as a loading control. (B) Weak acid stress-induced PDR12 promoter activity is dependent on WAR1. Logarithmically growing cells were treated with the indicated concentrations of weak organic acids for 45 min. β-galactosidase activity was determined in crude extracts. Wild-type: YAK3 PDR12-lacZ, war1Δ: YBB27 PDR12-lacZ war1Δ::HisMX6c.

The D antigen in the red cell membrane. The RhD protein consists of 417 amino acids (circles). All amino acid positions involved in the known, molecularly-defined weak D types are marked: weak D type 1, 2 and 3 (red), weak D type 4 cluster (yellow) and the additional 11 weak D types (orange) of the original description by . Many more amino acid substitutions have since been identified in one (grey) or several weak D types (blue) causing a serological weak D phenotype. Also, five rare subtypes of weak D type 1, 2 or 3 have been characterized that carry one additional amino acid substitution each (red ring). There are nine exon boundaries in the RHD cDNA (black bars), as reflected in the amino acid sequence (). Amino acid no. 1 is lacking from the mature protein in the red cell membrane, and the arch depicts the Rh protein vestibule (modified from ).

The packing of 2,3-difluorobenzoic acid shown along [010]. Hydrogen bonds are marked with blue, dashed lines. Weak C—H···F and C—H···O interactions are shown as light-blue, dashed lines.