Convergent evolution and targeting of diverse E2 epitopes by human broadly neutralizing antibodies are associated with HCV clearance.

The early appearance of broadly neutralizing antibodies (bNAbs) in serum is associated with spontaneous hepatitis C virus (HCV) clearance, but to date, the majority of bNAbs have been isolated from chronically infected donors. Most of these bNAbs use the V1-69 gene segment and target the envelope glycoprotein E2 front layer. Here, we performed longitudinal B cell receptor (BCR) repertoire analysis on an elite neutralizer who spontaneously cleared multiple HCV infections.

ADAR activation by inducing a syn conformation at guanosine adjacent to an editing site.

ADARs (adenosine deaminases acting on RNA) can be directed to sites in the transcriptome by complementary guide strands allowing for the correction of disease-causing mutations at the RNA level. However, ADARs show bias against editing adenosines with a guanosine 5' nearest neighbor (5'-GA sites), limiting the scope of this approach. Earlier studies suggested this effect arises from a clash in the RNA minor groove involving the 2-amino group of the guanosine adjacent to an editing site.

Functional and Structural Analysis of the Toxin-Binding Site of the Cadherin G-Protein-Coupled Receptor, BT-R, for Cry1A Toxins of .

The G-protein-coupled receptor BT-R in the moth represents a class of single-membrane-spanning α-helical proteins within the cadherin family that regulate intercellular adhesion and contribute to important signaling activities that control cellular homeostasis. The Cry1A toxins, Cry1Aa, Cry1Ab, and Cry1Ac, produced by bind BT-R very tightly ( = 1.1 nM) and trigger a Mg-dependent signaling pathway that involves the stimulation of G-protein α-subunit, which subsequently launches a coordinated signaling cascade, resulting in insect death.

Rational Design of RNA Editing Guide Strands: Cytidine Analogs at the Orphan Position.

Adenosine Deaminases Acting on RNA (ADARs) convert adenosine to inosine in double stranded RNA. Human ADARs can be directed to predetermined target sites in the transcriptome by complementary guide strands, allowing for the correction of disease-causing mutations at the RNA level. Here we use structural information available for ADAR2-RNA complexes to guide the design of nucleoside analogs for the position in the guide strand that contacts a conserved glutamic acid residue in ADARs (E488 in human ADAR2), which flips the adenosine into the ADAR active site for deamination.

Macromolecular crowding effects on the kinetics of opposing reactions catalyzed by alcohol dehydrogenase.

In order to better understand how the complex, densely packed, heterogeneous milieu of a cell influences enzyme kinetics, we exposed opposing reactions catalyzed by yeast alcohol dehydrogenase (YADH) to both synthetic and protein crowders ranging from 10 to 550 kDa. The results reveal that the effects from macromolecular crowding depend on the direction of the reaction. The presence of the synthetic polymers, Ficoll and dextran, decrease V and K for ethanol oxidation.

Overlap Concentration and the Effect of Macromolecular Crowding on Citrate Synthase Activity.

Although it is well-known that the environment of mitochondria is a densely packed network of macromolecules, the kinetics of the essential metabolic enzyme, citrate synthase, has been studied only under dilute conditions. To understand how this crowded environment impacts the behavior of citrate synthase, Michaelis-Menten kinetics were measured spectrophotometrically in the presence of synthetic crowders as a function of size, concentration, and identity. The largest factor contributing to crowding effects was the overlap concentration (*), the concentration above which polymers begin to interact.