Protein Complex Identification
Protein Complex Identification - Related Videos
10:07
Identification of Post-translational Modifications of Plant Protein Complexes
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Cited by 8 •
2014
We describe here a protocol for the purification and characterization of plant protein complexes. We demonstrate that by immunoprecipitating a single protein within a complex, so we can identify its post-translational modifications and its interacting partners.
11:12
Identification of protein complexes with quantitative proteomics in S. cerevisiae
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Cited by 4 •
2009
Here we describe a new quantitative proteomics technique for identifying protein complexes in Saccharomyces cerevisiae. In this study, we have used the SILAC method together with affinity purification followed by tandem mass spectrometry to identify with high specificity the binding partners of an ER protein, Scs2p.
02:41
Protein Complex Assembly
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2020
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes. Many viruses self-assemble into a fully functional unit using the infected host cell to...
01:57
Protein Complexes with Interchangeable Parts
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2020
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct. The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
13:34
Method for the Isolation and Identification of mRNAs, microRNAs and Protein Components of Ribonucleoprotein Complexes from Cell Extracts using RIP-Chip
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Cited by 19 •
2012
A step by step protocol to isolating and identifying RNA associated complexes through RIP-Chip.
FAQs
After associated proteins are isolated, mass spectrometry identifies them through characteristic peptide signatures. This connects the detected peptide patterns to particular protein components within the sample, allowing researchers to determine which proteins were recovered together. The resulting composition provides a basis for examining molecular machines and relating their protein membership to cellular functions.
These approaches provide different ways to isolate or preserve protein associations before identification. Co-immunoprecipitation and affinity purification are used to recover associated proteins, whereas cross-linking is paired with mass spectrometry to analyze proteins connected within a complex. Comparing results from these approaches can help characterize complex composition and interaction networks from complementary experimental perspectives.
Controls help distinguish specific protein associations from nonspecific binding during isolation. Without this comparison, proteins recovered from a sample could be mistaken for genuine complex components simply because they bind nonspecifically during the procedure. Including appropriate controls therefore improves confidence that the detected protein composition reflects a biologically meaningful assembly rather than background recovery.
The results can define complex composition and contribute to maps of interaction networks. Those maps place individual protein associations within broader cellular organization, helping researchers examine how molecular machines support processes such as signaling or gene regulation. Comparisons across developmental states or disease conditions can also reveal changes in complex assembly.
A typical workflow isolates associated proteins using co-immunoprecipitation, affinity purification, or cross-linking, then applies mass spectrometry to identify recovered proteins from their characteristic peptide signatures. Controls are included to evaluate nonspecific binding. Researchers can then interpret the identified components as complex composition, interaction-network information, or evidence of assembly differences between biological conditions.
This approach is useful when researchers need to investigate how proteins assemble into functional molecular machines. It supports studies of signaling, gene regulation, and cellular organization, and it can compare assemblies across developmental states or disease conditions. The resulting complex information may identify proteins for mechanistic investigation and provide targets for therapeutic research.