Pharmacokinetic and Pharmacodynamic Equivalence of Biosimilar and Reference Ultra-Rapid Lispro: A Comparative Clamp Study in Healthy Volunteers.

Ultra-rapid insulin lispro is an innovative insulin analogue designed to achieve rapid onset and short duration of action, aimed at optimizing glycemic control in patients with diabetes. This was a double-blind, randomized, 2-period, crossover clamp study to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD), along with safety profiles, of a potential biosimilar ultra-rapid insulin lispro compared to the reference product in healthy White men. A total of 35 healthy volunteers completed hyperinsulinemic euglycemic clamp procedures across both study periods.

Bioequivalence and Safety of Generic Glecaprevir/Pibrentasvir Compared to a Branded Product: A Randomized, Crossover Study in Healthy Volunteers.

This was an open-label, randomized, single-dose, 2-period, crossover clinical trial with an adaptive design to evaluate the bioequivalence and comparative pharmacokinetics of generic glecaprevir/pibrentasvir versus the brand name product in healthy White male and female volunteers under fed conditions. Safety profiles were also assessed. A total of 56 healthy adult volunteers were enrolled and randomly assigned in a 1:1 ratio to receive a single dose of either the generic or reference formulation.

Bioequivalence Study of Velpatasvir/Sofosbuvir Oral Coated Tablets in Healthy Volunteers Under Fasting Conditions.

This study was conducted as a single-site, open-label, randomized, replicated crossover trial with 4 treatment periods. The aim was to evaluate the bioequivalence of a generic test drug containing velpatasvir and sofosbuvir compared to an established brand-name medication in healthy White subjects under fasting conditions. Blood samples were collected at specified intervals up to 72 hours after dosing to measure the concentrations of velpatasvir and sofosbuvir using a certified high-performance liquid chromatography with tandem mass spectrometry method.

Clinical Pharmacology of GP40321 (Insulin Glulisine Biosimilar): Pharmacokinetic and Pharmacodynamic Comparability in a Hyperinsulinemic-Euglycemic Clamp Procedure.

The aim of the study was to compare the pharmacokinetics (PK) and pharmacodynamics (PD) of T-glu (GP40321, test drug), and reference insulin glulisine in a hyperinsulinemic-euglycemic clamp procedure. During this study, 34 healthy male volunteers underwent the hyperinsulinemic-euglycemic clamp procedure following subcutaneous 0.3 U/kg injection of T-glu or reference insulin glulisine in a randomized, double-blind, crossover study.

The voltage-sensing domain of a hERG1 mutant is a cation-selective channel.

A cationic leak current known as an "omega current" may arise from mutations of the first charged residue in the S4 of the voltage sensor domains of sodium and potassium voltage-gated channels. The voltage-sensing domains (VSDs) in these mutated channels act as pores allowing nonspecific passage of cations, such as Li, K, Cs, and guanidinium. Interestingly, no omega currents have been previously detected in the nonswapped voltage-gated potassium channels such as the human-ether-a-go-go-related (hERG1), hyperpolarization-activated cyclic nucleotide-gated, and ether-a-go-go channels.

Endocannabinoids enhance hK7.1/KCNE1 channel function and shorten the cardiac action potential and QT interval.

Background: Genotype-positive patients who suffer from the cardiac channelopathy Long QT Syndrome (LQTS) may display a spectrum of clinical phenotypes, with often unknown causes. Therefore, there is a need to identify factors influencing disease severity to move towards an individualized clinical management of LQTS. One possible factor influencing the disease phenotype is the endocannabinoid system, which has emerged as a modulator of cardiovascular function.

CryoEM structures of anion exchanger 1 capture multiple states of inward- and outward-facing conformations.

Anion exchanger 1 (AE1, band 3) is a major membrane protein of red blood cells and plays a key role in acid-base homeostasis, urine acidification, red blood cell shape regulation, and removal of carbon dioxide during respiration. Though structures of the transmembrane domain (TMD) of three SLC4 transporters, including AE1, have been resolved previously in their outward-facing (OF) state, no mammalian SLC4 structure has been reported in the inward-facing (IF) conformation. Here we present the cryoEM structures of full-length bovine AE1 with its TMD captured in both IF and OF conformations.

The Single Residue K12 Governs the Exceptional Voltage Sensitivity of Mitochondrial Voltage-Dependent Anion Channel Gating.

The voltage-dependent anion channel (VDAC) is a β-barrel channel of the mitochondrial outer membrane (MOM) that passively transports ions, metabolites, polypeptides, and single-stranded DNA. VDAC responds to a transmembrane potential by "gating," i.e.

A molecular switch controls the impact of cholesterol on a Kir channel.

SignificanceCholesterol is one of the main components found in plasma membranes and is involved in lipid-dependent signaling enabled by integral membrane proteins such as inwardly rectifying potassium (Kir) channels. Similar to other ion channels, most of the Kir channels are down-regulated by cholesterol. One of the very few notable exceptions is Kir3.

Cryo-EM structure of the sodium-driven chloride/bicarbonate exchanger NDCBE.

SLC4 transporters play significant roles in pH regulation and cellular sodium transport. The previously solved structures of the outward facing (OF) conformation for AE1 (SLC4A1) and NBCe1 (SLC4A4) transporters revealed an identical overall fold despite their different transport modes (chloride/bicarbonate exchange versus sodium-carbonate cotransport). However, the exact mechanism determining the different transport modes in the SLC4 family remains unknown.

Toward Reducing hERG Affinities for DAT Inhibitors with a Combined Machine Learning and Molecular Modeling Approach.

Psychostimulant drugs, such as cocaine, inhibit dopamine reuptake via blockading the dopamine transporter (DAT), which is the primary mechanism underpinning their abuse. Atypical DAT inhibitors are dissimilar to cocaine and can block cocaine- or methamphetamine-induced behaviors, supporting their development as part of a treatment regimen for psychostimulant use disorders. When developing these atypical DAT inhibitors as medications, it is necessary to avoid off-target binding that can produce unwanted side effects or toxicities.

A general mechanism of KCNE1 modulation of KCNQ1 channels involving non-canonical VSD-PD coupling.

Voltage-gated KCNQ1 channels contain four separate voltage-sensing domains (VSDs) and a pore domain (PD). KCNQ1 expressed alone opens when the VSDs are in an intermediate state. In cardiomyocytes, KCNQ1 co-expressed with KCNE1 opens mainly when the VSDs are in a fully activated state.

The origin and radiation of the phosphoprotein phosphatase (PPP) enzymes of Eukaryotes.

Phosphoprotein phosphatase (PPP) enzymes are ubiquitous proteins involved in cellular signaling pathways and other functions. Here we have traced the origin of the PPP sequences of Eukaryotes and their radiation. Using a bacterial PPP Hidden Markov Model (HMM) we uncovered "BacterialPPP-Like" sequences in Archaea.

Identification of PUFA interaction sites on the cardiac potassium channel KCNQ1.

Polyunsaturated fatty acids (PUFAs), but not saturated fatty acids, modulate ion channels such as the cardiac KCNQ1 channel, although the mechanism is not completely understood. Using both simulations and experiments, we find that PUFAs interact directly with the KCNQ1 channel via two different binding sites: one at the voltage sensor and one at the pore. These two amphiphilic binding pockets stabilize the negatively charged PUFA head group by electrostatic interactions with R218, R221, and K316, while the hydrophobic PUFA tail is selectively stabilized by cassettes of hydrophobic residues.

Lipid regulation of hERG1 channel function.

The lipid regulation of mammalian ion channel function has emerged as a fundamental mechanism in the control of electrical signalling and transport specificity in various cell types. In this work, we combine molecular dynamics simulations, mutagenesis, and electrophysiology to provide mechanistic insights into how lipophilic molecules (ceramide-sphingolipid probe) alter gating kinetics and K currents of hERG1. We show that the sphingolipid probe induced a significant left shift of activation voltage, faster deactivation rates, and current blockade comparable to traditional hERG1 blockers.

Polarization Effects in Water-Mediated Selective Cation Transport across a Narrow Transmembrane Channel.

Despite the progress in modeling complex molecular systems of ever-increasing complexity, a quantitatively accurate computational treatment of ion permeation through narrow membrane channels remains challenging. An important factor to reach this goal is induced electronic polarization, which is likely to impact the permeation rate of small ions through narrow molecular pores. In this work, we extended the recently developed polarizable force field based on the classical Drude oscillators to assess the role of induced polarization effects on the energetics of sodium and potassium ion transport across the gramicidin A (gA) ion channel.

Refinement of a cryo-EM structure of hERG: Bridging structure and function.

The human-ether-a-go-go-related gene (hERG) encodes the voltage-gated potassium channel (KCNH2 or Kv11.1, commonly known as hERG). This channel plays a pivotal role in the stability of phase 3 repolarization of the cardiac action potential.

Assessing hERG1 Blockade from Bayesian Machine-Learning-Optimized Site Identification by Ligand Competitive Saturation Simulations.

Drug-induced cardiotoxicity is a potentially lethal and yet one of the most common side effects with the drugs in clinical use. Most of the drug-induced cardiotoxicity is associated with an off-target pharmacological blockade of K currents carried out by the cardiac Human--Related (hERG1) potassium channel. There is a compulsory preclinical stage safety assessment for the hERG1 blockade for all classes of drugs, which adds substantially to the cost of drug development.

VDAC Gating Thermodynamics, but Not Gating Kinetics, Are Virtually Temperature Independent.

The voltage-dependent anion channel (VDAC) is the most abundant protein in the mitochondrial outer membrane and an archetypical β-barrel channel. Here, we study the effects of temperature on VDAC channels reconstituted in planar lipid membranes at the single- and multichannel levels within the 20°C to 40°C range. The temperature dependence of conductance measured on a single channel in 1 M KCl shows an increase characterized by a 10°C temperature coefficient Q = 1.