Induction Factors Causing Protein Aggregation Aggregation can be induced by a wide variety of conditions, including temperature, mechanical stress such as shaking and stirring, pumping, freezing and/or thawing and formulation.
How do you make protein aggregates?
Protein aggregation can occur through chemical or physical degradation and is dependent on the thermodynamic stability of the protein's native state. The driving force behind protein aggregation is the reduction in free surface energy by the removal of hydrophobic residues from contact with the solvent.
What is a possible cause of protein aggregation?
Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation.
What is the major cause of aggregation?
Some of the most common reasons proteins aggregate are; High concentration, a common problem found when overexpressing protein in bacteria. Conformational change, a switch from native to denatured that results in hydrophobic patches being exposed and aggregates being formed.
What types of interactions commonly lead to protein aggregation?
Environmental stresses such as extreme temperatures and pH or oxidative stress can also lead to protein aggregation. One such disease is cryoglobulinemia. Extreme temperatures can weaken and destabilize the non-covalent interactions between the amino acid residues.
Is protein aggregation good or bad?
Protein aggregation is a common characteristic of many neurodegenerative diseases. The aggregates and/or oligomers appear to be toxic, causing injury or death to cells. In general, the greater the degree of aggregation, the greater is the severity of disease.
How does protein aggregation work?
Protein aggregation is the process by which misfolded proteins adopt a conformation that cause its polymerization into aggregates and organized fibrils.
Why is protein aggregation important?
Protein aggregation Although the exact mechanism for aggregation has not been determined, it has been suggested that protein aggregates act to remove toxic, misfolded protein species and prevent them from interfering with cellular processes, conferring a protective benefit to the cell.
How do you prevent protein aggregation?
Tips for Preventing Protein Aggregation & Loss of Protein SolubilityPreventing Protein Aggregation: 5 Useful Tips to Consider.Maintain low protein concentration. ... Work at the right temperature. ... Change the pH of the solution. ... Change the salt concentration. ... Use an appropriate additive.
Can protein aggregation be reversed?
Abstract. Protein aggregation is mostly viewed as deleterious and irreversible causing several pathologies. However, reversible protein aggregation has recently emerged as a novel concept for cellular regulation. Here, we characterize stress-induced, reversible aggregation of yeast pyruvate kinase, Cdc19.
How do you test for protein aggregation?
Biochemical assays for monitoring protein aggregates often rely on ultracentrifugation, size-exclusion chromatography, gel electrophoresis, dynamic light scattering, or turbidity measurements.
Why do proteins aggregate at high temperatures?
High temperature induces the unfolding and exposure of hydrophobic stretches in thermosensitive proteins, which can establish non-native intra- and inter-molecular interactions leading to aggregation into high-order protein assemblies (Chiti and Dobson 2006; Kammerer et al.
Which force can lead to aggregation as a result of protein misfolding?
a) When proteins undergo misfolding, the aqueous environment in the cell exposes the hydrophobic amino acids at their cores. The exposed hydrophobic/nonpolar amino acids will interact with other hydrophobic/nonpolar amino acids to avoid water, generating aggregation.
What causes protein aggregation in Parkinson's?
Pathologically Parkinson's disease is characterized by loss of dopaminergic neurons in the compact part of substantia nigra. As a part of the neurodegenerative process protein aggregates will accumulate as Lewy bodies in dopaminergic neurons (1).
What protein aggregates in Alzheimer's?
The main protein component of amyloid in Alzheimer's disease is the 39–42 amino acid β-amyloid peptide (Aβ), which is a normal proteolytic breakdown product of the much larger membrane spanning amyloid precursor protein (APP; fig 1⇓). Structure of the amyloid precursor protein.
How do you prevent protein aggregation?
Tips for Preventing Protein Aggregation & Loss of Protein SolubilityPreventing Protein Aggregation: 5 Useful Tips to Consider.Maintain low protein concentration. ... Work at the right temperature. ... Change the pH of the solution. ... Change the salt concentration. ... Use an appropriate additive.
Which force can lead to aggregation as a result of protein misfolding?
a) When proteins undergo misfolding, the aqueous environment in the cell exposes the hydrophobic amino acids at their cores. The exposed hydrophobic/nonpolar amino acids will interact with other hydrophobic/nonpolar amino acids to avoid water, generating aggregation.
What is protein aggregation and what factors influence protein aggregation?
Protein aggregation is undesired interaction between protein monomers and can be caused by factors such as pH, ionic strength, mechanical agitation, protein concentration, freeze-thaw operations, temperature, and packaging materials and agents (such as glass and silicone oil).
How does protein aggregation affect bioprocess?
Over the past decade, protein-based therapeutics have emerged as a key driver of growth in the pharmaceutical industry. The efficient large scale production of recombinant proteins requires careful handling of the protein during isolation and purification. Proteins are isolated in an environment devoid of potentially stabilizing factors.
What are efficient methods to detect protein aggregation?
Understanding the fundamental mechanism of aggregation is valuable for identifying the factors underlying the problem and further aid in developing strategies to prevent aggregation.
PROTEOSTASIS
Proteostasis, or protein homeostasis, is the collective term used to describe a variety of cellular processes designed to minimize damage from altered, misfolded, and otherwise damaged proteins.
PROTEASOMES
One significant component of the proteostasis network is carried out by proteasomes, multisubunit complexes within the nucleus and cytoplasm that degrade soluble protein, according to Alfred Goldberg of Harvard Medical School. The vast majority of damaged proteins are normally degraded by proteasomes, and so too are smaller protein aggregates.
AUTOPHAGY AND LYSOSOMES
Autophagy is a dynamic process of bulk degradation of cellular organelles and proteins; this includes proteins that are soluble as well as those that form into oligomers and aggregates. Autophagy clears them from the cell by lysosomes rather than by proteasomes, whose catalytic core is too narrow for bulk material to enter.
ENDOPLASMIC RETICULUM STRESS AND THE UNFOLDED PROTEIN RESPONSE
Recent findings show a strong correlation between the aggregation of misfolded proteins and the engagement of a stress response of the endoplasmic reticulum (ER), said Claudio Hetz, a professor at the University of Chile.
RESEARCH NEEDS AND NEXT STEPS SUGGESTED BY INDIVIDUAL PARTICIPANTS
The speakers at the workshop identified many questions for future research and other opportunities for future action. The research suggestions related to protein aggregation are compiled here to provide a sense of the range of suggestions made.
Popular Answers (1)
See the following link: https://www.pharmtech.com/view/excipient-selection-protein-stabilization
All Answers (13)
You might be able to moderate the aggregation by either increasing or decreasing the salt concentration.
Similar questions and discussions
I have a protein tagged with MBP (maltose binding protein)with a TEV cleavage site between MBP and prot. How to improve the cleavage of the tag?
Significance
Proteins are inherently sensitive to environmental factors that include hydrodynamic flow. Flow-induced protein remodeling is used in vivo and can also trigger the aggregation of therapeutic proteins during manufacture. Currently, the relative importance of shear and extensional hydrodynamic flow fields to aggregation remains unclear.
Abstract
Relative to other extrinsic factors, the effects of hydrodynamic flow fields on protein stability and conformation remain poorly understood. Flow-induced protein remodeling and/or aggregation is observed both in Nature and during the large-scale industrial manufacture of proteins.
Discussion
Whereas prior work has demonstrated that hydrodynamic flow can induce the unfolding of supercoiled plasmid DNA ( 20, 27 ), polymers ( 26 ), von Willebrand factor ( 21, 46 ), and other proteins ( 11 ), the relative ability of shear and extensional flow to induce aggregation for these different systems has remained unclear.
Data Availability
Data deposition: All data are available from the Research Data Leeds Repository, archive.researchdata.leeds.ac.uk (accession URL: https://doi.org/10.5518/125 ).
Acknowledgments
We thank Prof. Joanne Tipper and Dr. Saurabh Lal for their help with NTA, and Mr. David Sharples for access to the ultracentrifuge facility. We thank Prof. Peter Olmsted for many insightful discussions at the inception of this work. J.D. and A.K. are cofunded by MedImmune Ltd. and the University of Leeds. L.F.W.
Abstract
For reducing protein aggregation in foam fractionation, the role of pH-induced structural change in the interface-induced protein aggregation was analyzed using bovine serum albumin (BSA) as a model protein.
Acknowledgments
This work was financially supported by Natural Science Foundations of China (21346008 and 21236001) and Graduate Student Innovation Foundation of Hebei, China (220056).
