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

Catalysis02:50

Catalysis

The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Enzymes02:34

Enzymes

Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Introduction to Enzymes01:22

Introduction to Enzymes

The use of enzymes by humans dates to 7000 BCE. Humans first used enzymes to ferment sugars and produce alcohol without knowing that this was an enzyme-catalyzed reaction. Wilhelm Kuhne coined the term 'enzyme' in 1877 from the Greek words ‘en’ meaning ‘in’ or ‘within’ and ‘zyme’ meaning ‘yeast.’
Most enzymes are proteins that speed up biochemical reactions without being consumed. Enzymes contain one or more active sites that bind the substrates and convert them into products. Many enzymes also...
Introduction to Mechanisms of Enzyme Catalysis01:13

Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
Introduction to Mechanisms of Enzyme Catalysis01:13

Introduction to Mechanisms of Enzyme Catalysis

For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
Catalysis01:27

Catalysis

Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...

You might also read

Related Articles

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

Sort by
Same author

Oxidative Characteristics of Turkey Hemoglobin A Containing Covalently Bound Epigallocatechin Gallate.

Journal of agricultural and food chemistry·2026
Same author

Structural investigation of QatB and QatC proteins in QatABCD anti-phage defense.

Nature communications·2026
Same author

Proteomic Characterization of AS1411 Reveals ATP6AP1 as a Mediator of Triple-Negative Breast Cancer Progression.

Proteomics·2026
Same author

Farewell and thank you note.

Structural dynamics (Melville, N.Y.)·2026
Same author

Structural characterization of anti-CRISPR protein AcrIE9.

Structural dynamics (Melville, N.Y.)·2025
Same author

Sequence-based calculation of local energetic frustration in proteins.

Structural dynamics (Melville, N.Y.)·2025
Same journal

Tesorai Search: cloud-based database search engine boosts identifications for mass spectrometry proteomics with a pretrained peptide-spectrum deep-learning model.

Journal of molecular biology·2026
Same journal

Characterization of diverse functions of NRF1 nuclear localization sequence.

Journal of molecular biology·2026
Same journal

UPF3A and UPF3B shape the transcriptome cooperatively yet oppose cell function.

Journal of molecular biology·2026
Same journal

Antibody-secreting cells integrate efficient NMD with non‑canonical UPR signaling to maintain proteostasis and support massive immunoglobulin synthesis.

Journal of molecular biology·2026
Same journal

Small molecule stabilization of diverse amyloidogenic immunoglobulin light chains revealed by hydrogen-deuterium exchange mass spectrometry.

Journal of molecular biology·2026
Same journal

UPF1 at Work: Structural and Mechanistic Insights Into a Master Regulator of Nonsense-Mediated mRNA Decay.

Journal of molecular biology·2026
See all related articles

Related Experiment Video

Updated: Jun 12, 2026

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
08:25

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)

Published on: January 17, 2020

Structural basis for catalysis by onconase.

J Eugene Lee1, Euiyoung Bae, Craig A Bingman

  • 1Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706-1544, USA.

Journal of Molecular Biology
|November 16, 2007
PubMed
Summary
This summary is machine-generated.

Onconase (ONC), a cancer-treating enzyme, uses specific interactions to distinguish between guanine and adenine bases in RNA. Modifications can alter this preference, but wild-type ONC remains the most effective against cancer cells.

More Related Videos

Modeling an Enzyme Active Site using Molecular Visualization Freeware
14:37

Modeling an Enzyme Active Site using Molecular Visualization Freeware

Published on: December 25, 2021

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
12:08

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes

Published on: June 24, 2022

Related Experiment Videos

Last Updated: Jun 12, 2026

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)
08:25

Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks (MOFs)

Published on: January 17, 2020

Modeling an Enzyme Active Site using Molecular Visualization Freeware
14:37

Modeling an Enzyme Active Site using Molecular Visualization Freeware

Published on: December 25, 2021

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
12:08

Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes

Published on: June 24, 2022

Area of Science:

  • Biochemistry
  • Structural Biology
  • Enzymology

Background:

  • Onconase (ONC) is a ribonuclease A homolog from Rana pipiens with demonstrated antitumoral activity.
  • ONC is currently in advanced clinical trials for cancer treatment.
  • Understanding ONC's substrate specificity is crucial for its therapeutic application.

Purpose of the Study:

  • To determine the atomic structures of Onconase-nucleic acid complexes.
  • To elucidate the molecular basis for substrate recognition and catalytic turnover by ONC.
  • To investigate how specific mutations affect ONC's substrate preference and activity.

Main Methods:

  • X-ray crystallography was used to obtain atomic structures of ONC-nucleic acid complexes.
  • Site-directed mutagenesis was employed to create ONC variants with altered residues.
  • Enzyme kinetics (k(cat)/K(M)) were measured to quantify substrate preference and catalytic efficiency.

Main Results:

  • Atomic structures revealed key residues involved in binding nucleic acids, including interactions with guanine and adenine bases.
  • Mutations at positions 89 and 91 significantly altered ONC's preference between guanine and adenine.
  • A T89N/E91A ONC variant showed a preference for adenine, while E91R increased guanine preference.
  • A T5R substitution enhanced ribonucleolytic activity by twofold.
  • No engineered ONC variant exhibited greater toxicity to human cancer cells than wild-type ONC.

Conclusions:

  • ONC discriminates between guanine and adenine through a combination of Coulombic interactions and hydrogen bonding networks.
  • Specific amino acid substitutions can modulate ONC's base preference and catalytic efficiency.
  • Wild-type ONC possesses optimal cytotoxic activity against cancer cells, highlighting its therapeutic potential.
  • These structural and mechanistic insights provide a foundation for understanding RNA cleavage catalysis in a medically relevant enzyme.