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 Experiment Videos

Enhanced protein thermostability by Ala-->Aib replacement

V De Filippis1, F De Antoni, M Frigo

  • 1CRIBI Biotechnology Centre, University of Padua, Italy.

Biochemistry
|March 4, 1998
PubMed
Summary

Incorporating alpha-aminoisobutyric acid (Aib) into proteins can enhance their stability. Replacing alanine with Aib in thermolysin subdomain 255-316 increased its melting temperature, demonstrating a general protein stabilization strategy.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Abstracts of the 6th FECS Conference 1998 Lectures.

Environmental science and pollution research international·2008
Same author

Temporally controlled modulation of antihydrogen production and the temperature scaling of antiproton-positron recombination.

Physical review letters·2008
Same author

Neutron scattering study of the vibrations in vitreous silica and germania.

The Journal of chemical physics·2008
Same author

Damping of sound waves in the terahertz range and strength of the boson peak.

The Journal of chemical physics·2008
Same author

Phase II study of sequential chemotherapy with docetaxel-estramustine followed by mitoxantrone-prednisone in patients with advanced hormone-refractory prostate cancer.

British journal of cancer·2007
Same author

[Early infantile and late infantile form of Krabbe disease: CT and MRI findings].

La Pediatria medica e chirurgica : Medical and surgical pediatrics·2007

Area of Science:

  • Protein Engineering
  • Biochemistry
  • Structural Biology

Background:

  • Alpha-aminoisobutyric acid (Aib) incorporation stabilizes short peptide helical structures by limiting backbone conformations.
  • The carboxy-terminal subdomain 255-316 of thermolysin, a 62-residue fragment, forms a dimer and possesses a 3-alpha-helix structure consistent with intact thermolysin.

Purpose of the Study:

  • To evaluate the protein-level stabilizing effect of alpha-aminoisobutyric acid (Aib) incorporation.
  • To investigate the conformational and stability properties of Aib-containing analogs of the thermolysin carboxy-terminal subdomain 255-316.

Main Methods:

  • Semisynthetic approach to create Aib-containing analogs of thermolysin fragment 255-316 by replacing specific alanine residues with Aib.
  • Characterization using far- and near-UV circular dichroism to assess secondary and tertiary structures.

Related Experiment Videos

  • Thermal unfolding monitored by ellipticity at 222 nm to determine melting temperatures (Tm).

    • Main Results:

    • Secondary and tertiary structures were fully retained in Aib-substituted analogs compared to the natural fragment.
    • Melting temperatures (Tm) increased by 2.2°C (Ala304Aib) and 5.4°C (Ala309Aib), while Ala312Aib showed a slight decrease (-0.6°C).
    • Double substitution (Ala304Aib/Ala309Aib) resulted in an additive Tm increase of +8°C, indicating significant stabilization.

    Conclusions:

    • Rational incorporation of alpha-aminoisobutyric acid (Aib) can significantly stabilize proteins.
    • Stabilization effects are attributed to reduced backbone entropy and, in buried positions, hydrophobic effects.
    • Unfavorable strain energy can counteract stabilization if Aib substitution occurs at positions with restricted conformational angles.