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

Export of Misfolded Proteins out of the ER01:32

Export of Misfolded Proteins out of the ER

5.4K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
5.4K
Protein Folding Quality Check in the RER01:29

Protein Folding Quality Check in the RER

5.4K
ER is the primary site for the maturation and folding of soluble and transmembrane secretory proteins. The calnexin cycle is a specific chaperone system that folds and assesses the confirmation of N-glycosylated proteins before they can exit the ER lumen. The primary players of this quality check pipeline are the lectins, ER-resident chaperones, and a glucosyl transferase enzyme. In case the calnexin system in the lumen fails to salvage a misfolded protein, it is transported to the cytoplasm...
5.4K
Oligosaccharide Assembly01:24

Oligosaccharide Assembly

3.8K
Protein glycosylation starts in the ER lumen and continues in the Golgi apparatus. Glycosyltransferases catalyze the addition of sugar molecules or glycosylation of proteins. Usually, these enzymes add sugars to the hydroxyl groups of selected serine or threonine residues to form O-linked glycans or the amino groups of asparagine residues to form N-linked glycans. Different positions on the same polypeptide chain can contain differently linked glycans.
Multiple sugar molecules that may or may...
3.8K
Protein Transport to the Inner Chloroplast Membrane01:18

Protein Transport to the Inner Chloroplast Membrane

2.5K
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
2.5K
Protein Transport to the Stroma01:24

Protein Transport to the Stroma

2.3K
Chloroplasts are triple membrane structures with an outer membrane, an inner membrane, and a thylakoid membrane, each containing distinct metabolite transporters, membrane translocons, and enzymes. Appropriate sorting and translocating these proteins to their correct membrane systems is essential for chloroplast function.
Protein complexes called the translocon of the outer chloroplast membrane or TOC complex, and the translocon of the inner chloroplast membrane or TIC complex mediate the...
2.3K
Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

13.6K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
13.6K

You might also read

Related Articles

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

Sort by
Same author

Discovery of Bacterial Unspecific Peroxygenases.

Biochemistry·2026
Same author

Redox robustness drives LPMO evolution.

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

Reduced Processivity in a Chitobiohydrolase Enhances LPMO-Assisted Chitin Depolymerization.

Biochemistry·2026
Same author

Structural and electronic modulations of lytic polysaccharide monooxygenase (LPMO) upon chitin binding: insights from X-ray spectroscopy.

Chemical science·2025
Same author

Structure-function relationships in unspecific peroxygenases revealed by a comparative study of their action on the phenolic lignin monomer 4-propylguaiacol.

Biotechnology for biofuels and bioproducts·2025
Same author

Structure-Function Analysis of an Understudied Type of LPMO with Unique Redox Properties and Substrate Specificity.

ACS catalysis·2025

Related Experiment Video

Updated: Mar 8, 2026

Measurement of Chitinase Activity in Biological Samples
03:32

Measurement of Chitinase Activity in Biological Samples

Published on: August 22, 2019

10.9K

Human Chitotriosidase Is an Endo-Processive Enzyme.

Silja Kuusk1, Morten Sørlie2, Priit Väljamäe1

  • 1Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.

Plos One
|January 28, 2017
PubMed
Summary

Human chitotriosidase (HCHT) acts as an endo-processive enzyme on crystalline chitin. Its action and binding properties fall between bacterial exo- and endo-chitinases, with the CBM enhancing chitin affinity.

More Related Videos

Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve
09:13

Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve

Published on: June 14, 2017

13.5K
Glycoproteomics of the Extracellular Matrix: A Method for Intact Glycopeptide Analysis Using Mass Spectrometry
14:02

Glycoproteomics of the Extracellular Matrix: A Method for Intact Glycopeptide Analysis Using Mass Spectrometry

Published on: April 21, 2017

13.2K

Related Experiment Videos

Last Updated: Mar 8, 2026

Measurement of Chitinase Activity in Biological Samples
03:32

Measurement of Chitinase Activity in Biological Samples

Published on: August 22, 2019

10.9K
Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve
09:13

Optimized Protocol for the Extraction of Proteins from the Human Mitral Valve

Published on: June 14, 2017

13.5K
Glycoproteomics of the Extracellular Matrix: A Method for Intact Glycopeptide Analysis Using Mass Spectrometry
14:02

Glycoproteomics of the Extracellular Matrix: A Method for Intact Glycopeptide Analysis Using Mass Spectrometry

Published on: April 21, 2017

13.2K

Area of Science:

  • Biochemistry
  • Enzymology
  • Immunology

Background:

  • Human chitotriosidase (HCHT) is crucial for immune responses against chitinous pathogens.
  • HCHT degrades chitooligosaccharides and crystalline chitin, with two active isoforms identified in humans.
  • Its active site resembles bacterial chitinase ChiA, but structural features suggest similarities to non-processive endo-chitinase SmChiC.

Purpose of the Study:

  • To thoroughly characterize HCHT's mode of action, processivity, binding, and kinetic constants on crystalline α-chitin.
  • To elucidate whether HCHT acts as an endo- or exo-acting enzyme on insoluble chitin substrates.

Main Methods:

  • Enzyme kinetics and activity assays using α-chitin as a substrate.
  • Characterization of HCHT's processivity and binding affinity.
  • Analysis of catalytic and dissociation rate constants.

Main Results:

  • HCHT demonstrated efficient endo-mode initiation (95% probability) on processive runs.
  • The enzyme released end-labels from reducing-end labeled chitin, confirming endo-activity.
  • HCHT's processivity and dissociation rates were intermediate between processive exo-enzymes (SmChiA) and non-processive endo-enzymes (SmChiC).

Conclusions:

  • HCHT functions as an endo-processive enzyme on crystalline chitin.
  • The carbohydrate-binding module (CBM) primarily enhances chitin affinity without significantly altering kinetic properties.
  • HCHT's unique enzymatic characteristics position it uniquely among chitinases.