Related Experiment Video
Updated: Jul 12, 2026
08:51
Monitoring Protein Adsorption with Solid-state Nanopores
Published on: December 2, 2011
How to open a proton pore-more than S4?
Marcel P Goldschen-Ohm1, Baron Chanda1
1Departments of Neuroscience and Biomolecular Chemistry, University of Wisconsin, Madison, Wisconsin, USA.
Nature Structural & Molecular Biology
|April 4, 2015
Summary
New research reveals distinct movements in helix S1 correlate with proton channel pore opening, differing from the voltage-sensing domain S4 helix movements in voltage-gated ion channels.
Area of Science:
- Ion channel biophysics
- Molecular and cellular physiology
- Membrane protein dynamics
Background:
- Voltage-gated potassium channels' voltage-sensing domain (VSD) S4 helix movements are well-characterized.
- The mechanism of proton pore opening in VSDs of voltage-dependent proton channels remains less understood.
Purpose of the Study:
- To investigate the local kinematics associated with proton channel pore opening.
- To differentiate proton pore opening mechanisms from VSD S4 helix movements.
Main Methods:
- Systematic probing of local kinematics within voltage-dependent proton channels.
- Analysis of helix movements and their correlation with pore gating.
Main Results:
- Movements in helix S1 were found to correlate with proton channel pore opening.
- These S1 helix movements are distinct from the voltage-sensing movements of the charged S4 segment.
Conclusions:
- Proton channel gating involves unique conformational changes in helix S1.
- Understanding these distinct movements is crucial for elucidating proton transport mechanisms.
More Related Videos
Related Concept Videos
01:47Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they...
01:29Primary Active Transport
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction they would not...
01:27ATP Driven Pumps I: An Overview
ATP-driven pumps, also known as transport ATPases, are integral membrane proteins. They have binding sites for ATP located on the membrane's cytosolic side and the ion-conducting domain in the transmembrane region. These pumps use the free energy released from ATP hydrolysis to move the solutes across cell membranes against an electrochemical gradient.
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
There are four main types of ATP-driven pumps - P-type, V-type, F-type, and ABC transporter. All these pumps are of varying complexities and are...
01:12Porin Insertion in the Outer Mitochondrial Membrane
Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...
01:34ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
01:21Structure of Porins
Mitochondria, chloroplasts, and gram-negative bacteria have transmembrane, beta-barrel proteins called porins to mediate the free diffusion of ions and metabolites across the membrane. Mitochondrial porin precursors contain conserved amino acid sequences called beta signals at their C-terminal. Beta signals have a motif of PoXGXXHyXHy (Po-Polar, X-Any amino acid, G-Glycine, Hy-LargeHydrophobic), which are crucial for precursor recognition to initiate precursor assembly. Beta-barrel precursors...