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Published on: December 25, 2021
Expanding the Concepts in Protein Structure-Function Relationships and Enzyme Kinetics: Teaching using Morpheeins
Sarah H Lawrence1, Eileen K Jaffe
1Fox Chase Cancer Center, 333 Cottman Ave, Philadelphia PA, 19111.
Summary
Morpheins are proteins that regulate function through alternate quaternary assemblies, not misfolded states. Understanding these dynamic protein structures offers a new model for allosteric regulation.
Area of Science:
- Biochemistry
- Structural Biology
- Protein Dynamics
Background:
- Morpheins are homo-oligomeric proteins capable of forming multiple, distinct functional quaternary structures.
- These alternate assemblies arise from conformational equilibria between different tertiary structures, representing distinct native states.
Purpose of the Study:
- To introduce the concept of morpheeins as a novel class of proteins with dynamic regulatory capabilities.
- To highlight the unique allosteric regulation model offered by morpheeins.
- To discuss barriers in recognizing and studying morpheeins.
Main Methods:
- Characterization of the prototype enzyme, porphobilinogen synthase, as a model morpheein.
- Analysis of transitions between alternate morpheein assemblies involving dissociation and reassembly.
- Exploration of environmental influences (e.g., effector molecules) on morpheein transitions.
Main Results:
- Porphobilinogen synthase exists in a dynamic equilibrium of an octamer, hexamer, and dimer conformations.
- Morpheins represent a new paradigm for allosteric regulation through conformational shifts and reassembly.
- Identified intellectual and experimental barriers hindering morpheein recognition.
Conclusions:
- Morpheins are likely prevalent in nature and represent a significant, underappreciated mechanism of protein regulation.
- Revisiting fundamental concepts in protein biochemistry is necessary to fully appreciate morpheeins.
- Encourages the integration of morpheein concepts into biochemistry education.
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