21: Binding and Association
- Page ID
- 294358
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Molecular associations are at the heart of biological processes. Specific functional interactions are present at every level of cellular activity. Some of the most important:
1)Proteins Interacting with Small Molecules and Ions
- Enzyme/substrate interactions and catalysis
- Ligand/receptor binding
- Chemical energy transduction (for instance ATP)
- Signaling (for instance neurotransmitters, cAMP)
- Drug or inhibitor binding
- Antibody binding antigen
- Small molecule and ion transport
- Mb + O2 → MbO2
- Ion channels and transporters
2) Protein–Protein Interactions
- Signaling and regulation networks
- Receptors binding to ligands activate receptors
- GPCRs bind agonist/hormone for transmembrane signal transduction
- Assembly and function of multi-protein complexes
- Replication machinery in replisome consists of multiple proteins including DNA polymerase, DNA ligase, topoisomerase, helicase
- Kinetochore orchestrate interactions of chromatin and the motor proteins that separate sister chromatids during cell division
3) Protein–Nucleic Acid Interactions
- All steps in the central dogma
- Transcription factor binding
- DNA repair machinery
- Ribozymes
In all of these examples, the common thread is a macromolecule, which typically executes a conformational change during the interaction process. Conformational flexibility and entropy changes during binding play an important role in describing these processes.