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

Amyloid Fibrils03:03

Amyloid Fibrils

12.5K
Amyloid fibrils are aggregates of misfolded proteins.  Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils. 
Amyloid deposits were observed as early as 1639 in the liver and the spleen.   In 1854, Rudolph Virchow performed iodine staining,...
12.5K
Amyloid Fibrils03:03

Amyloid Fibrils

6.9K
6.9K
Enzymes02:34

Enzymes

96.4K
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...
96.4K
Induced-fit Model01:13

Induced-fit Model

91.1K
Most chemical reactions in cells require enzymes—biological catalysts that speed up the reaction without being consumed or permanently changed. They reduce the activation energy needed to convert the reactants into products. Enzymes are proteins, that usually work by binding to a substrate—a reactant molecule that they act upon.
Enzymes exhibit substrate specificity, meaning that they can only bind to certain substrates. This is mainly determined by the shape and chemical...
91.1K
Introduction to Mechanisms of Enzyme Catalysis01:13

Introduction to Mechanisms of Enzyme Catalysis

11.2K
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...
11.2K
Allosteric Proteins-ATCase01:19

Allosteric Proteins-ATCase

6.8K
Binding sites linkages can regulate a protein's function.  For example, enzyme activity is often regulated through a feedback mechanism where the end product of the biochemical process serves as an inhibitor.
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to  N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis...
6.8K

You might also read

Related Articles

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

Sort by
Same author

Synthetic Substrate Discovery for Hck Kinase via Phage Display.

Biochemistry·2026
Same author

Study on the Self-Assembly and Dual-Stimuli-Responsive Behavior of Multi-amphiphilic Polymeric Architectures.

Polymer science & technology (Washington, D.C.)·2026
Same author

Structure-Activity Relationship Study of Antimicrobial Peptide with Cross-Kingdom Activity.

Biochemistry·2026
Same author

A hydrolase from Serratia liquefaciens IMD717 with esterase, dehalogenase and N-deformylase activities.

Applied microbiology and biotechnology·2026
Same author

Reversed-phase chromatography of peptides carrying non-canonical proline analogues, with special focus on 4R/4S-fluoroproline.

Journal of chromatography. A·2026
Same author

Metal Ion-Induced Cross-Linking in Mucin-Inspired Peptide Hydrogels.

Journal of peptide science : an official publication of the European Peptide Society·2025

Related Experiment Video

Updated: Mar 11, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
08:53

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Published on: March 21, 2025

1.2K

Substrate specificity of an actively assembling amyloid catalyst.

Jason L Heier1, Dorian J Mikolajczak1, Christoph Böttcher2

  • 1Freie Universität Berlin Department of Biology, Chemistry, Pharmacy Institute of Chemistry and Biochemistry Berlin, Germany.

Biopolymers
|November 19, 2016
PubMed
Summary
This summary is machine-generated.

The catalytic peptide Ac-IHIHIQI-NH2 shows enhanced selectivity for hydrophobic substrates during self-assembly, driven by interactions with exposed hydrophobic surfaces. This peptide offers valuable insights for designing novel catalysts.

Keywords:
catalysisde novopeptideself-assemblyzinc-bound hydroxide

More Related Videos

Characterizing Individual Protein Aggregates by Infrared Nanospectroscopy and Atomic Force Microscopy
12:58

Characterizing Individual Protein Aggregates by Infrared Nanospectroscopy and Atomic Force Microscopy

Published on: September 12, 2019

10.3K
Rapid Generation of Amyloid from Native Proteins In vitro
05:48

Rapid Generation of Amyloid from Native Proteins In vitro

Published on: December 5, 2013

6.5K

Related Experiment Videos

Last Updated: Mar 11, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
08:53

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids

Published on: March 21, 2025

1.2K
Characterizing Individual Protein Aggregates by Infrared Nanospectroscopy and Atomic Force Microscopy
12:58

Characterizing Individual Protein Aggregates by Infrared Nanospectroscopy and Atomic Force Microscopy

Published on: September 12, 2019

10.3K
Rapid Generation of Amyloid from Native Proteins In vitro
05:48

Rapid Generation of Amyloid from Native Proteins In vitro

Published on: December 5, 2013

6.5K

Area of Science:

  • Biochemistry
  • Materials Science
  • Catalysis

Background:

  • Amyloid-forming peptides can self-assemble into ordered structures.
  • Catalytic peptides offer potential for novel chemical transformations.
  • Peptide self-assembly can create unique microenvironments influencing reactivity.

Purpose of the Study:

  • To investigate the influence of Zn2+ on the catalytic activity and substrate selectivity of the amyloid-forming peptide Ac-IHIHIQI-NH2.
  • To explore how the peptide's self-assembly state affects its catalytic performance.
  • To understand the role of hydrophobic interactions in substrate binding and catalysis.

Main Methods:

  • Synthesis and characterization of the catalytic peptide Ac-IHIHIQI-NH2.
  • Kinetic studies of ester hydrolysis using various p-nitrophenyl substrates (e.g., p-nitrophenyl acetate, Z-L-Phe-ONp, Boc-L-Asn-ONp) in the presence of Zn2+.
  • Comparison of catalytic activity in different peptide aggregation states (assembling vs. fully fibrillar).
  • Enantioselectivity studies using Z-Phe-ONp.

Main Results:

  • Zn2+ promotes the self-assembly of Ac-IHIHIQI-NH2 into amyloid fibrils.
  • The assembling peptide exhibited significantly enhanced catalytic activity ( >11-fold increase in second-order rate constant) towards the hydrophobic substrate Z-L-Phe-ONp compared to its fully fibrillar state.
  • Under assembly conditions, the peptide showed increased selectivity for the L-enantiomer of Z-Phe-ONp.
  • Hydrolysis of the more hydrophilic ester Boc-L-Asn-ONp was slower than Z-L-Phe-ONp when the peptide was assembling.

Conclusions:

  • The self-assembly process of Ac-IHIHIQI-NH2 creates hydrophobic surfaces that enhance interactions with hydrophobic substrates.
  • The peptide's catalytic activity and selectivity are modulated by its aggregation state, favoring hydrophobic substrates during assembly.
  • These findings highlight the potential of using self-assembling peptides as tunable catalysts and inform future de novo catalyst design.