Questions tagged [proteins]
For questions about proteins. Proteins are biopolymers consisting primarily of polycondensated amino acids.
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How can I determine if there are π-π interactions between an amide and an aromatic ring in a protein?
In a crystal structure I've determined, a triazole ring on my ligand appears to be stacking with a tyrosine (top in picture):
However, there is also an amide, courtesy a glutamine, near it (bottom). ...
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Why is the cyanide ion toxic?
As the title implies, what is the molecular basis of cyanide toxicity? I did some searching around at the CDC and it only states that it prevents cells from using oxygen. I also read how it could take ...
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What makes heat resistant proteins heat resistant?
We were doing the chapter Biomolecules in class the other day, and a doubt popped up once we reached the section on proteins.
We were taught that the stuff that keeps proteins together are: Ionic ...
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What is the nature of the Fe–O2 binding in oxymyoglobin and oxyhemoglobin?
Deoxymyoglobin ($\ce{Mb}$) is known to have iron in the +2 oxidation state; I believe this was deduced from its magnetic moment, which corresponds to four unpaired electrons in high-spin $\mathrm{d^6}$...
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Why do unboiled eggs last longer than boiled eggs?
Just like the title says, I watched this video https://youtu.be/CHMY4G9gTPA and then became intrigued.
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Why do the physical properties of an egg shell change when the egg shell is exposed to vinegar for a week?
When an egg is kept in vinegar for one week, its hard calcium carbonate shell changes into a soft rubbery membrane. As vinegar is weak acetic acid, how does vinegar change calcium carbonate into a ...
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Why does this lysozyme powder not look crystalline?
I am very new to protein crystallography and visualization. I have been asked to take photos through an optical microscope of the lysozyme powder directly as-is from the supplier. I suspended some of ...
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AChE Aging time of organophosphorus compounds containing hydroxyl groups
Organophosphorus compounds are known to inhibit the enzyme acetylcholinesterase (AChE). This occurs when the OPC phosphorylates the serine-203 residue of the enzyme. If the enzyme is not reactivated ...
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Does quantum mechanics play a role in protein folding?
Protein folding takes a very long time (relatively speaking) when thinking of quantum mechanical effect. However, for the initial micro-steps of folding, when an atom, or a configuration of atoms, can ...
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Why is collagen fibre autofluorescent?
Why is collagen fibre autofluorescent? Proteins with increased amount of trp, tyr, phe tend to fluoresce but I don't think collagen fibre has increased percentage of any of them. Some say collagen ...
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Why aren't chaperones considered catalysts?
I'm reading about protein folding on Wikipedia and I stumbled on a bit about a class of proteins called chaperones that aid in the folding of proteins by:
...reducing possible unwanted aggregations ...
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Why are hydrogen bonds in an antiparallel beta sheet stronger than those in parallel beta sheets?
Beta sheets are illustrated as such in most diagrams, where:
In an antiparallel β-sheet, the polypeptide strands are arranged such that a $\ce{C=O}$ and an $\ce{NH}$ from adjacent strands face each ...
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How to dock aggregated structures comprised of "elementary" protein units like LEGO pieces?
There are proteins with intrinsic symmetries. For example:
I was wondering how to use transformations such as: rotations, translation, replications to construct possible structures using 2 types of ...
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Q-TOF vs Q-orbitrap MS data
I recently had the opportunity to analyze the same (intact protein) sample on an Agilent QTOF and a Thermo Q-Exactive, and noticed that in addition to having a moderately higher resolution the ...
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Is it known for sure that bases feel slippery because of the production of soap/surfactant?
Discussion around the question Why does bleach feel slippery? has started me thinking about the saponification explanation for the slippery feeling of basic solutions.
According to Wikipedia:
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