Related Experiment Video
Updated: Jun 28, 2026
08:37
Measuring Enzymatic Stability by Isothermal Titration Calorimetry
Published on: March 26, 2019
Conformational changes in bovine lactoferrin induced by slow or fast temperature increases
Waleska D Schwarcz1, Lorena Carnelocce, Jerson L Silva
1Mestrado em Ciência e Tecnologia do Leite, Universidade Norte do Paraná, 86041-100 Londrina, PR, Brazil.
Biological Chemistry
|November 4, 2008
Summary
Heat affects bovine lactoferrin (LF) structure, altering its tertiary but not secondary structure during pasteurization. This suggests LF may form a partially folded state, impacting its use in food products.
Area of Science:
- Biochemistry
- Food Science
- Protein Chemistry
Background:
- Lactoferrin (LF) is an iron-binding protein with antimicrobial and physiological functions, found in milk.
- Protein stability and functionality can be compromised by high temperatures, affecting its applications.
Purpose of the Study:
- To investigate the impact of heat on the structure and stability of bovine lactoferrin (LF).
- To understand how pasteurization temperatures affect LF's protein functionality.
Main Methods:
- Spectroscopic techniques, including circular dichroism (CD) and fluorescence spectroscopy, were used to monitor conformational changes.
- Simulated pasteurization processes were employed to assess LF stability under relevant conditions.
Main Results:
- Elevated temperatures (e.g., 70°C and 25°C–105°C) drastically and irreversibly altered LF's secondary structure, as shown by CD and fluorescence spectroscopy.
- During simulated pasteurization, LF maintained structural integrity, indicating heat stability that was not time-dependent.
- While secondary structure was preserved, tertiary structure changes suggested LF might transition to a partially folded intermediate state.
Conclusions:
- Pasteurization may induce a partially folded state in bovine lactoferrin, altering its tertiary structure.
- Understanding the heat stability of LF is crucial for its effective utilization as a bioactive component in food products.
Related Concept Videos
01:26Bacterial Protein Maturation
Bacterial protein maturation is a tightly regulated process that ensures newly synthesized polypeptides achieve correct functional conformations. This maturation involves a series of modifications, folding events, and quality control steps, often assisted by specialized chaperone proteins.N-Terminal ModificationsThe maturation of bacterial polypeptides begins cotranslationally as the polypeptide exits the ribosome. The first amino acid, N-formylmethionine (fMet), is typically modified at the...
02:28Effect of Temperature Change on Reaction Rate
The Arrhenius equation,
02:11Effects of Temperature on Free Energy
The spontaneity of a process depends upon the temperature of the system. Phase transitions, for example, will proceed spontaneously in one direction or the other depending upon the temperature of the substance in question. Likewise, some chemical reactions can also exhibit temperature-dependent spontaneities. To illustrate this concept, the equation relating free energy change to the enthalpy and entropy changes for the process is considered:
01:29Microbes in Food Production
Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...
02:55Temperature Dependence on Reaction Rate
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
01:28Protein Denaturation
The function of proteins depends on their native three-dimensional structure, which is dictated by the amino acid sequence of the specific protein. Folding of the polypeptide chain takes place under specific conditions that energetically favor the folded conformation. In contrast, protein denaturation occurs spontaneously under unfavorable conditions that disrupt the integrity of the folded conformation. Thus, the chemical and physical environment of a protein, such as significant changes in pH...