Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Nitric Oxide Signaling Pathway01:28

Nitric Oxide Signaling Pathway

Nitric oxide (NO), an inorganic gas, acts as a potent second messenger in most animal and plant tissues. NO diffuses out of the cells that produce it and enters the neighboring cells to generate a downstream response. NO synthase (NOS) catalyzes NO production by the deamination of the amino acid arginine. There are three isoforms of NOS. Endothelial cells have endothelial NOS (eNOS), nerve and muscle cells have neuronal NOS (nNOS), and macrophages produce inducible NOS (iNOS) upon exposure to...
Ligand-Gated Ion Channel Receptor: Gating Mechanism01:30

Ligand-Gated Ion Channel Receptor: Gating Mechanism

Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
Antihypertensive Drugs: Vasodilators01:23

Antihypertensive Drugs: Vasodilators

Vasodilators, primarily affecting the smooth muscles within arterial and venous walls, are commonly used for hypertension treatment. Medications such as minoxidil and hydralazine primarily target arteries and arterioles, while sodium nitroprusside acts on arterioles and venules. Minoxidil, functioning as a prodrug, is metabolized by hepatic sulfotransferase into its active form, minoxidil sulfate, after oral administration. This metabolite binds to the sulfonylurea receptor (SUR) component of...
Activation and Inactivation of G Proteins01:22

Activation and Inactivation of G Proteins

Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...
GPCR Desensitization01:12

GPCR Desensitization

G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
G-Protein Gated Ion Channels01:21

G-Protein Gated Ion Channels

GPCRs are primarily responsible for our sense of smell, taste, and vision.  The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory organs,...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Multistep electron tunneling through tryptophans in the KatG bifunctional peroxidase monitored by a nonperturbing spin probe.

Proceedings of the National Academy of Sciences of the United States of America·2026
Same author

Next generation protein-corrole bio-assemblies provide effective tumoricidal treatment in a metastatic triple-negative breast cancer model.

bioRxiv : the preprint server for biology·2026
Same author

Electron Transport through a Tryptophan Quadruplex in a Dimeric Azurin Construct.

The journal of physical chemistry. B·2026
Same author

Cooperative ligand binding in a bacterial heme-based oxygen sensor.

The Journal of biological chemistry·2025
Same author

Oxidizable amino acids around cytochrome P450 hemes.

Journal of inorganic biochemistry·2025
Same author

Roles of biological heme-based sensors of O<sub>2</sub> in controlling bacterial behavior.

Journal of inorganic biochemistry·2025

Related Experiment Video

Updated: May 26, 2026

Application of Genetically Encoded Fluorescent Nitric Oxide (NO&#8226;) Probes, the geNOps, for Real-time Imaging of NO&#8226; Signals in Single Cells
08:32

Application of Genetically Encoded Fluorescent Nitric Oxide (NO•) Probes, the geNOps, for Real-time Imaging of NO• Signals in Single Cells

Published on: March 16, 2017

Gating NO release from nitric oxide synthase.

Charlotte A Whited1, Jeffrey J Warren, Katherine D Lavoie

  • 1Beckman Institute and Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.

Journal of the American Chemical Society
|December 14, 2011
PubMed
Summary

We studied nitric oxide (NO) release from Geobacillus stearothermophilus nitric oxide synthase (gsNOS). Mutating specific sites revealed that both positions 223 and 134 act as gates, controlling NO escape.

More Related Videos

En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries
08:58

En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries

Published on: February 25, 2016

Measurement of Cyclic Guanosine Monophosphate (cGMP) in Solid Tissues using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)
07:15

Measurement of Cyclic Guanosine Monophosphate (cGMP) in Solid Tissues using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)

Published on: July 3, 2025

Related Experiment Videos

Last Updated: May 26, 2026

Application of Genetically Encoded Fluorescent Nitric Oxide (NO&#8226;) Probes, the geNOps, for Real-time Imaging of NO&#8226; Signals in Single Cells
08:32

Application of Genetically Encoded Fluorescent Nitric Oxide (NO•) Probes, the geNOps, for Real-time Imaging of NO• Signals in Single Cells

Published on: March 16, 2017

En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries
08:58

En Face Detection of Nitric Oxide and Superoxide in Endothelial Layer of Intact Arteries

Published on: February 25, 2016

Measurement of Cyclic Guanosine Monophosphate (cGMP) in Solid Tissues using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)
07:15

Measurement of Cyclic Guanosine Monophosphate (cGMP) in Solid Tissues using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)

Published on: July 3, 2025

Area of Science:

  • Biochemistry
  • Enzymology
  • Molecular Biology

Background:

  • Nitric oxide synthases (NOS) are crucial enzymes in biological systems.
  • Previous studies suggested a gating mechanism for nitric oxide (NO) release in mammalian NOS.
  • The structure and function of bacterial NOS, like Geobacillus stearothermophilus NOS (gsNOS), are less understood regarding NO release kinetics.

Purpose of the Study:

  • To investigate the kinetics of NO escape from wild-type gsNOS.
  • To determine the role of specific amino acid residues (position 223 and 134) in regulating NO release from gsNOS.
  • To compare the NO release rates of gsNOS with known mammalian NOS enzymes.

Main Methods:

  • Stopped-flow UV-vis spectroscopy was used to monitor reactions.
  • Kinetic experiments were performed on wild-type gsNOS and specific mutants (H134S, I223V, H134S/I223V).
  • Reactions were initiated by mixing a reduced enzyme/N-hydroxy-l-arginine complex with aerated buffer.

Main Results:

  • Wild-type gsNOS exhibits the slowest NO release rate among characterized NOS enzymes.
  • Mutations at positions 223 and 134 significantly increased the rate of NO escape.
  • The double mutant (H134S/I223V) displayed NO release rates comparable to the fastest mammalian NOS enzymes.
  • Steric hindrance at positions 223 and 134 was identified as a key factor impeding NO release.

Conclusions:

  • Both positions 223 and 134 in gsNOS function as critical gates controlling the release of NO.
  • Modulating these gate residues can dramatically alter NO release kinetics.
  • Understanding these gating mechanisms provides insights into NOS enzyme function and regulation across different species.