SOPRANO: Macitentan in patients with pulmonary hypertension following left ventricular assist device implantation.

Macitentan is a dual endothelin receptor antagonist (ERA) approved for treating pulmonary arterial hypertension (PAH). SOPRANO evaluated the efficacy and safety of macitentan versus placebo in pulmonary hypertension (PH) patients after left ventricular assist device (LVAD) implantation. SOPRANO was a phase 2, multicenter, double-blind, randomized, placebo-controlled, parallel-group study.

Twin-arginine translocase component TatB performs folding quality control via a chaperone-like activity.

The twin-arginine translocation (Tat) pathway involves an inbuilt quality control (QC) system that synchronizes the proofreading of substrate protein folding with lipid bilayer transport. However, the molecular details of this QC mechanism remain poorly understood. Here, we hypothesized that the conformational state of Tat substrates is directly sensed by the TatB component of the bacterial Tat translocase.

Engineering a Supersecreting Strain of by Directed Coevolution of the Multiprotein Tat Translocation Machinery.

remains one of the preferred hosts for biotechnological protein production due to its robust growth in culture and ease of genetic manipulation. It is often desirable to export recombinant proteins into the periplasmic space for reasons related to proper disulfide bond formation, prevention of aggregation and proteolytic degradation, and ease of purification. One such system for expressing heterologous secreted proteins is the twin-arginine translocation (Tat) pathway, which has the unique advantage of delivering correctly folded proteins into the periplasm.

An engineered genetic selection for ternary protein complexes inspired by a natural three-component hitchhiker mechanism.

The bacterial twin-arginine translocation (Tat) pathway is well known to translocate correctly folded monomeric and dimeric proteins across the tightly sealed cytoplasmic membrane. We identified a naturally occurring heterotrimer, the Escherichia coli aldehyde oxidoreductase PaoABC, that is co-translocated by the Tat translocase according to a ternary "hitchhiker" mechanism. Specifically, the PaoB and PaoC subunits, each devoid of export signals, are escorted to the periplasm in a piggyback fashion by the Tat signal peptide-containing subunit PaoA.

Twin-arginine translocase mutations that suppress folding quality control and permit export of misfolded substrate proteins.

The bacterial twin-arginine translocation (Tat) pathway facilitates the transport of correctly folded proteins across the tightly sealed cytoplasmic membrane. Here, we report the isolation and characterization of suppressor mutations in the Tat translocase that allow export of misfolded proteins, which form structures that are not normally tolerated by the wild-type translocase. Selection of suppressors was enabled by a genetic assay that effectively linked in vivo folding and stability of a test protein with Tat export efficiency of a selectable marker protein, namely TEM-1 β-lactamase.

Engineering antibody fitness and function using membrane-anchored display of correctly folded proteins.

A hallmark of the bacterial twin-arginine translocation (Tat) pathway is its ability to export folded proteins. Here, we discovered that overexpressed Tat substrate proteins form two distinct, long-lived translocation intermediates that are readily detected by immunolabeling methods. Formation of the early translocation intermediate Ti-1, which exposes the N- and C-termini to the cytoplasm, did not require an intact Tat translocase, a functional Tat signal peptide, or a correctly folded substrate.

SecA interacts with ribosomes in order to facilitate posttranslational translocation in bacteria.

In Escherichia coli, translocation of exported proteins across the cytoplasmic membrane is dependent on the motor protein SecA and typically begins only after synthesis of the substrate has already been completed (i.e., posttranslationally).

Genetic selection of solubility-enhanced proteins using the twin-arginine translocation system.

The expression of heterologous proteins in robust hosts such as Escherichia coli is often plagued by the tendency of the protein of interest to misfold and aggregate. To engineer and improve the folding properties of virtually any protein of interest, the quality control process inherent to the bacterial twin- arginine translocation (Tat) pathway can be exploited. The Tat pathway preferentially transports folded substrates across the inner membrane of E.

Site-specific labeling of surface proteins on living cells using genetically encoded peptides that bind fluorescent nanoparticle probes.

We report a highly specific, robust, and generic method for noncovalent labeling of cellular proteins with highly fluorescent core-shell silica nanoparticles termed C dots. Our approach uses short genetically engineered peptides with affinity for silica (GEPS) that are site-specifically introduced at the termini or in loops of cellular proteins. Because GEPS are absent from native cell surface proteins, GEPS-tagged recombinant proteins can be selectively and rapidly labeled with fluorescent C dots.

Peptide amphiphile nanostructure-heparin interactions and their relationship to bioactivity.

Heparin-protein interactions are important in many physiological processes including angiogenesis, the growth of new blood vessels from existing ones. We have previously developed a highly angiogenic self-assembling gel, wherein the self-assembly process is triggered by the interactions between heparin and peptide amphiphiles (PAs) with a consensus heparin binding sequence. In this report, this consensus sequence was scrambled and incorporated into a new peptide amphiphile in order to study its importance in heparin interaction and bioactivity.

Self-assembled monolayers of an oligo(ethylene oxide) disulfide and its corresponding thiol assembled from water: characterization and protein resistance.

Self-assembled monolayers (SAMs) of the disulfide [S(CH2CH2O)6CH3]2 ([S(EO)6]2) on Au from 95% ethanol and from 100% water are described. Spectroscopic ellipsometry and reflection-absorption infrared spectroscopy indicate that the [S(EO)6]2 films are similar to the disordered films of HS(CH2CH2O)6CH3 ((EO)6) and HS(CH2)3O(CH2CH2O)5CH3 (C3EO5) at their protein adsorption minima. The [S(EO)6]2 SAMs exhibit constant film thickness (d) of 1.