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Full-Text Articles in Life Sciences
The Gating Charge Should Not Be Estimated By Fitting A Two-State Model To A Q-V Curve, Francisco Bezanilla, Carlos A. Villalba-Galea
The Gating Charge Should Not Be Estimated By Fitting A Two-State Model To A Q-V Curve, Francisco Bezanilla, Carlos A. Villalba-Galea
School of Pharmacy Faculty Articles
The voltage dependence of charges in voltage-sensitive proteins, typically displayed as charge versus voltage (Q-V) curves, is often quantified by fitting it to a simple two-state Boltzmann function. This procedure overlooks the fact that the fitted parameters, including the total charge, may be incorrect if the charge is moving in multiple steps. We present here the derivation of a general formulation for Q-V curves from multistate sequential models, including the case of infinite number of states. We demonstrate that the commonly used method to estimate the charge per molecule using a simple Boltzmann fit is not only inadequate, but in …
Sensing Charges Of The Ciona Intestinalis Voltage-Sensing Phosphatase, Carlos A. Villalba-Galea, Ludivine Frezza, Walter Sandtner, Francisco Bezanilla
Sensing Charges Of The Ciona Intestinalis Voltage-Sensing Phosphatase, Carlos A. Villalba-Galea, Ludivine Frezza, Walter Sandtner, Francisco Bezanilla
School of Pharmacy Faculty Articles
Voltage control over enzymatic activity in voltage-sensitive phosphatases (VSPs) is conferred by a voltage-sensing domain (VSD) located in the N terminus. These VSDs are constituted by four putative transmembrane segments (S1 to S4) resembling those found in voltage-gated ion channels. The putative fourth segment (S4) of the VSD contains positive residues that likely function as voltage-sensing elements. To study in detail how these residues sense the plasma membrane potential, we have focused on five arginines in the S4 segment of the Ciona intestinalis VSP (Ci-VSP). After implementing a histidine scan, here we show that four arginine-to-histidine mutants, namely R223H to …
Lipophilic Stinging Nettle Extracts Possess Potent Anti-Inflammatory Activity, Are Not Cytotoxic And May Be Superior To Traditional Tinctures For Treating Inflammatory Disorders., Tyler A. Johnson, Johann Sohn, Wayne D Inman, Leonard F. Bjeldanes, Keith Rayburn
Lipophilic Stinging Nettle Extracts Possess Potent Anti-Inflammatory Activity, Are Not Cytotoxic And May Be Superior To Traditional Tinctures For Treating Inflammatory Disorders., Tyler A. Johnson, Johann Sohn, Wayne D Inman, Leonard F. Bjeldanes, Keith Rayburn
Natural Sciences and Mathematics | Faculty Scholarship
Extracts of four plant portions (roots, stems, leaves and flowers) of Urtica dioica (the stinging nettle) were prepared using accelerated solvent extraction (ASE) involving water, hexanes, methanol and dichloromethane. The extracts were evaluated for their anti-inflammatory and cytotoxic activities in an NF-κB luciferase and MTT assay using macrophage immune (RAW264.7) cells. A standardized commercial ethanol extract of nettle leaves was also evaluated. The methanolic extract of the flowering portions displayed significant anti-inflammatory activity on par with a standard compound celastrol (1) but were moderately cytotoxic. Alternatively, the polar extracts (water, methanol, ethanol) of the roots, stems and leaves displayed moderate …
Loss Of Dendritic Inhibition In The Hippocampus After Repeated Early-Life Hyperthermic Seizures In Rats., Richard Boyce, L Stan Leung
Loss Of Dendritic Inhibition In The Hippocampus After Repeated Early-Life Hyperthermic Seizures In Rats., Richard Boyce, L Stan Leung
Physiology and Pharmacology Publications
Seizures are relatively common in children and are a risk factor for subsequent temporal lobe epilepsy. To investigate whether early-life seizures themselves are detrimental to the proper function of the adult brain, we studied whether dendritic excitation and inhibition in the hippocampus of adult rats were altered after hyperthermia-induced seizures in immature rats. In particular, we hypothesized that apical dendritic inhibition in hippocampal CA1 pyramidal cells would be disrupted following hyperthermia-induced seizures in early life. Seizure rats were given three hyperthermia-induced seizures per day for three days from postnatal day (PND) 13 to 15; control rats were handled similarly but …