Questions tagged [protein-interaction]

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Is tyrosine hydrophobic or hydrophilic?

I’ve seen tyrosine classified as a hydrophobic amino acid due to its aromatic ring in some textbooks and as hydrophilic due to its hydroxyl group in other textbooks. How does tyrosine actually ...
P...'s user avatar
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1 answer
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Where can I find large datasets of protein-interaction networks?

Where do I find large datasets of protein interaction networks for cancer or alzheimer diseases? So far, I found String but it is does not have enough proteins for my purposes. Are there such ...
A M's user avatar
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Help with STRING database data

I'm working with data downloaded from STRING database (string-db.org) for protein-protein interactions. My idea is to compare the topology of connections of the same protein on different organisms. ...
Zé Ricardo's user avatar
4 votes
1 answer
231 views

How does one derive a KD from an equilibrium titration experiment?

If I have an antibody A and a target B, and experimentally titrate the antibody against a single concentration of B, and then measure the % of B that is bound after the solutions reach equilibrium, I ...
Justin's user avatar
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1 answer
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protein-binding sRNAs

I am actually a computational biologist, pardon me if my question description is a bit off-note, my curiosity is driving me on A bit of background and context: In bacteria, a regulatory protein ...
bioSlayer's user avatar
4 votes
1 answer
114 views

How does HIV assemble its capsid correctly?

HIV’s capsid is very unusual. The capsid is made of around 1200 identical CA proteins (p24). These CA proteins first assemble into either pentamers or hexamers, which assemble into a fullerene like ...
哲煜黄's user avatar
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3 votes
1 answer
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How many proteins could participate in a complex

Disclaimer: I’m a computer science student with minimum knowledge of biology. I’m working on an algorithm to cluster proteins in Protein-Protein-Interaction Networks to find protein-complexes. While ...
obvg's user avatar
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3 votes
3 answers
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Biological validation of computationally determined gene-gene interaction

How can a computationally determined three-way gene interaction be biologically validated? What kind of assays or tests must be performed using cell/tissue-based and/or mouse models to prove that the ...
Coolfunk's user avatar
3 votes
1 answer
3k views

What is the significance in an alpha-helix being right-handed or left-handed?

Why is that often when alpha-helices are discussed, it is also mentioned their direction - right-handed (clockwise) or left-handed (anti-clockwise)? I have heard that left-handed alpha-helices are ...
Aalawlx's user avatar
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3 votes
1 answer
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I2D vs STRING for protein-protein interactions

Can someone clearly explain me the differences between STRING and I2D(Interlogous interaction database) ? What does each database do best ? Which database is better for what kinds of studies etc ?
user avatar
3 votes
2 answers
2k views

difference between motifs, domains, patterns, signatures and profiles

I can't get clear the difference between those terms, I see them a lot while browsing on Prosite, Pfam, Expasy e.t.c. However, I can find documentation about them, but It still not clear what the ...
KingBoomie's user avatar
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How do prions transmit their conformation to other proteins?

I was reading about prions and many sources say something to this effect: "Prions may propagate by transmitting their misfolded protein state: When a prion enters a healthy organism, it induces ...
Gabriel's user avatar
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How to interpret the relationships of PTMs from BioGRID's data

On BioGRID Database, PTMREL is a file that describes relationships of the PTMs (Post Translation Modification) tabulated in a PTMTAB file. I have several issues with this file. Foremost, I am not ...
user345394's user avatar
2 votes
2 answers
195 views

Are multi-chain proteins synthesized as one biological unit?

Are multi-chain proteins (especially homo/hetero-dimers) synthesized together as one overall unit or are they separate monomers which bind together at some point after synthesis, and are there any ...
Aalawlx's user avatar
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2 votes
1 answer
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Why are VAL, MET and ALA substitutions commonly used for protein behaviour and function studies?

I have seen that amino acids are commonly replaced with VAL, MET or ALA to study the effects of these specific substitutions. Why are these specific amino acids used in particular, what are the ...
Aalawlx's user avatar
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2 votes
2 answers
109 views

Determining the appropriate bioconjugate

I'm thinking of crosslinking two proteins. The crystallographic nature of the interaction and the binding motif for each molecule is know. The paper says the intermolecular contacts (over 50; van der ...
Behzad Rowshanravan's user avatar
2 votes
1 answer
173 views

In protein-protein interactions what is the difference between a binding site and an interface?

I see binding site and interface used almost interchangeably in the literature, but I'm not sure if it is exactly the same thing or not - what is the difference?
Aalawlx's user avatar
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1 answer
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How does the body detect irreversible binding to receptors?

I have read an article on Wikipedia about irreversible agonists and antagonists. These permanently bind to a target receptor on a cell. However, the receptor protein is then internalized and recycled ...
user73910's user avatar
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1 answer
854 views

Does urea at different concentrations (5 or 0.5M) have different effects on proteins?

The problem is to explain why each additive gives rise to the distribution of the protein (RMAS) as shown in the Western blow below: In each case, the homogenates were subjected to high-speed ...
justbehappy's user avatar
2 votes
1 answer
392 views

Stabilizing forces between the protein sequences?

we know that Protein structures from secondary to Quaternary are maintained by noncovalent or weak interactions including electrostatic interactions,van der Waals forces & hydrogen bonding. What ...
katherinebridges's user avatar
2 votes
1 answer
46 views

Will the interaction of two proteins vary across different tissues? [closed]

Suppose protein A and B is both abundant in tissue X an tissue Y. Will A and B interact in X but not interact in Y? I guess A and B could be biomarkers of a certain disease, and in the pathological ...
Wei Feng's user avatar
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2 votes
1 answer
189 views

How do proteins perform their function [closed]

I have asked a question on physics stackexchange, but was redirected here. I copy the entire question word for word. The original is here. Let's, for example, take a ribosome. It is an enzyme that is ...
Anton's user avatar
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1 answer
48 views

Fluorescent protein tags and colocalisation

We want study if 2 proteins A and B are co-located, for that we use 2 FTP(Fluorescent tag proteins) for each protein?and after the expirement these 2 FTP are co-located. Does that mean necessarily ...
Maickel Tawdrous's user avatar
2 votes
0 answers
37 views

What is the actual mechanism by which ApoA-1 Milano exhibits its phenotype?

ApoA-1Milano is a variant of the apolipoprotein A-I protein that was discovered by the University of Milan when sequencing the genome of those native to the village Limone sul Garda. The mutation has ...
小奥利奥's user avatar
2 votes
0 answers
50 views

What is the "GTP activator protein" that activates GTP-cyclohydrolase-1?

From GTP-cyclohydrolase deficiency responsive to sapropterin and 5-HTP supplementation: relief of treatment-refractory depression and suicidal behaviour (BMJ Case Reports, 2011) The metabolic profile ...
CopperKettle's user avatar
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2 votes
0 answers
38 views

functionality of protein based on amino acid covalently linked to something

This question is directly taken off from "challenge question" as part of my bio-engineering class. The functionality of any individual protein covalently linked to a device is dependent on the ...
Jason Kim's user avatar
2 votes
0 answers
82 views

String-db locally downloaded

I need a ppi network of cancer and it should have 200k to 300k proteins (nodes) As the web inteface don't allow more than 2000 ...
A M's user avatar
  • 155
2 votes
0 answers
176 views

How to quantify the "stability" of a protein complex?

From experiment we've identified a subset of known mammalian protein complexes as interesting (approximately 50 CORUM complexes). We'd like to do an enrichment-style analysis to know more about them. ...
R Greg Stacey's user avatar
2 votes
2 answers
114 views

Protein-protein interactions search

I used STRING db in order to find all the interactions of the precursor protein APP. What I specifically need is a confirmation (supported by some article and experiments in it). But significant ...
L. Bird's user avatar
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2 votes
0 answers
90 views

How to predict cancer-related proteins in Protein-Protein Interaction networks [closed]

Protein-Protein Interaction networks are known. It's an undirected graph. Each row of the networks is like this (Protein 2 - Protein 6), and It represents the interaction between Protein 2 and Protein ...
user2405694's user avatar
2 votes
0 answers
39 views

Interaction study of oligomeric proteins

I'm dealing with two different protein(say, protein_a and protein_b) which stays in an interacting-oligomeric form in biological system. I have so far successfully been able to purify both the ...
diffracteD's user avatar
2 votes
0 answers
49 views

What is the protein with the highest affinity to lactose?

I was wondering: What is the protein with the highest affinity to lactose? Are there some databases with values for affinity?
Pao's user avatar
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1 vote
1 answer
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Why bovine serum albumin is used in mass-spectroscopy and how to interpret such data?

In the paper Network organization of the huntingtin proteomic interactome in mammalian brain, there is a description of a mass spectroscopy experiment where Bovine Serum Albumin (BSA) is added to a ...
Noob's user avatar
  • 257
1 vote
1 answer
117 views

Application of molecular dynamics simulation (or alternatives) for the full pathways of protein interactions?

If one would like to control the biological system (e.g. to treat disease or aging/senescence) then one should introduce the drugs in the system, that initiate complex protein interaction pathways ...
TomR's user avatar
  • 103
1 vote
2 answers
825 views

Alternatives to His-tags

What are the alternatives to using a histidine-tag in detecting protein-protein interactions? Why would they be more beneficial than his-tags?
Esther's user avatar
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1 vote
1 answer
70 views

Binding BSA to silver surface via large difference in isoelectric points of the two materials

I would like to bind BSA to a silver surface so that I can utilize plasmonic sensing to detect the BSA. There seems to be two methods of doing this: 1) to rely on electrostatic forces or 2) to form a ...
ngc1300's user avatar
  • 111
1 vote
1 answer
134 views

Do RNA modification proteins bind to specific repeats on the RNA polymerase II CTD?

The C-terminal domain (CTD) of human RNA polymerase II has 52 repeats of a similar heptapeptide sequence. Will the RNA modification proteins only bind to some repeats at specific locations on this (e....
jw_'s user avatar
  • 181
1 vote
1 answer
38 views

Query regarding KEGG KGML pathway files

With respect to the the Wnt pathway in KEGG, the KGML file of this pathway has description of each interaction between a pair of genes. These interactions are designated in the form: ...
girl101's user avatar
  • 2,215
1 vote
1 answer
74 views

How to predict Protein-Protein Interactions from a pair of gene symbols?

I have a list of pairs of gene symbols who interact (putatively) and would like to assign each pair a score (and record other details) based on the predicted Protein-Protein Interaction (PPI). The ...
Joshua Garrison Burkhart's user avatar
1 vote
1 answer
69 views

How is Glycophorin A and straphylococcal related to Escherichia coli and what does readily purified mean in this context?

I am reviewing the paper "Glycophorin A Dimerization Is Driven by Specific Interactions between Transmembrane Alpha-Helices." There is a statement in the abstract which I don't understand: "The ...
Aalawlx's user avatar
  • 423
1 vote
1 answer
912 views

What are the differences between HPRD and BIOGRID databases?

What are the differences between HPRD and BIOGRID protein-protein interactions databases? What are their purposes? Why do we need two different databases? How is data collected into each one? How ...
Uri's user avatar
  • 349
1 vote
1 answer
62 views

False positives in TAP - MS experiments

Is anyone aware of a website where they show common false positives often found when doing a TAP-MS experiment to find protein-protein interaction experiments? Particularly the Acs1 protein (Acetyl-...
Loko's user avatar
  • 11
1 vote
1 answer
59 views

What are the types of interactions in biological network (protein networks)?

In the KGML files, the types of relations between genes or proteins are precisely activation, inhibition, expression, repression, indirect effect, state change, binding/association, dissociation, ...
girl101's user avatar
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1 vote
1 answer
1k views

What's the difference between physical (direct) and functional (indirect) protein interaction?

I read that the Protein-Protein interactions one can consider are generally of two types, namely physical and functional, but I cannot get the difference between the two. I was just thinking that if ...
Noired's user avatar
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1 vote
1 answer
180 views

Rules of motif forming

I want to understand how a motif is present or not, can be deduced from a PDB file. Are there any rule of thumb for forming 3D motifs? Like a series of helices and sheets in some direction will lead ...
girl101's user avatar
  • 2,215
1 vote
1 answer
746 views

Why are low throughput methods more trustable for protein interaction?

I read that protein interactions found using high throughput methods are less trustable than those found using low throughput methods. For example, searching for interaction of BRCA2 on BioGRID, I ...
biogirl's user avatar
  • 8,599
1 vote
0 answers
20 views

Should Secondary Antibody Bind better through adsorption than using an EDC Linker?

Recently, I conducted an experiment to compare the use of EDC versus passive adsorption. I attempted to immobilize goat anti-rabbit HRP secondary antibody to Carboxylated polystyrene beads via EDC ...
Matthew Huang's user avatar
1 vote
0 answers
11 views

What are the interaction energies/chemical potential values for the cytoplasm - protein interactions within the cytoplasm?

I'm trying to simulate phase separation in a biological based system using a Cahn Hilliard model. I have 3 components, they are 2 theoretical enzymes and the cytoplasm. I have found plenty of sources ...
JollyBioComputer's user avatar
1 vote
0 answers
31 views

Peak-calling in CLIP: What is the effect of RNA-concentration?

I hope it's ok to repost my question from 8 months ago from StackExchange:Bioinformatics, that is still in beta. https://bioinformatics.stackexchange.com/questions/10730/peak-calling-in-clip-what-is-...
KaPy3141's user avatar
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1 vote
0 answers
39 views

Get Network Out of proteins of interest

I have generated a list of Proteins using oncogeenes and suppressor genes of cancer. I have 5827 mapping identifier for 3916 interactions using STRINGdb R package . How do I build a network of 200k ...
A M's user avatar
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