Questions tagged [proteins]

Biopolymers consisting of amino acids that fold into 3D shapes and perform a large number of functions in living organisms.

Proteins consist of one or more large amino acid residues and perform a vast array of functions in living organisms. Questions may need to draw on alternative related tags, such as , , and .

Additional, more-precise tags exist for proteins and should be additionally used as appropriate:

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Are there any examples of proteins with no or minimal sequence identity, but highly similar structure?

What are they, and do they share a common ancestor? How far back in evolutionary time must we go to find them? If none are known, what computational tools might be used to search for such examples?
luminousfish
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Can any protein be phosphorylated?

I am working with an Arabidopsis mutant with an F-box protein knocked out. It has been shown that F-box proteins targets must first be phosphorylated (Skowrya et al., 1997). I have heard of phosphorylation sites, but I can't find out whether every…
Rik Smith-Unna
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How does Yeast-two-hybrid detect interactions between several proteins in one experiment?

I am trying to understand the Y2H screening method. I can understand how we can check if two specific proteins interact with each other. For example, if we want to check whether protein A and protein B interact, we fuse A with the Activation Domain…
Vinayak Pathak
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Is there a protein in the eye that gets kinked by photons and shipped down to the liver to get un-kinked?

My friend made the claim that there exists a protein in your eye responsible for vision. This protein is sensitive to different wavelengths of light, and when it gets hit by the right wavelength, it kinks. In order to be un-kinked, he claimed, it…
ochemnewb
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Solvent Accessibility, the 20% cut-off method

I'm reading the papers linked below and all three of them mention a 20% cut-off for buried/exposed residues, by calculating a relative solvent accessibility (RSA) value. I understand how the RSA is calculated, by dividing the calculated solvent…
harpalss
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Protein Biology Cheat Sheet

I'm looking find a cheat sheet for protein biology to stick on my desk to remind of some of the key principles of protein biology. I seem to remember the specific and complex principles in protein biology but at the expense of the basics. Can anyone…
harpalss
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When does oxidation destroy prions?

It seems like a no-brainer than oxidation, playing the, er, role it does in the universe, would destroy prions just like it destroys everything else. But when does it do that? I assume this has been studied, since people handle them in laboratories…
magnetar
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Can proteins/peptides pass through the intestine?

I've heard somewhere said that : Stomach cells do not absorb anything larger than single amino acids. Is that wrong? How do biological toxins (peptides/proteins) from mushroom or bacteria like Botulinum come to our blood and affect our body after…
joe
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Are all protein composed of all the amino acid (in animal) or are there less diverse protein?

I have a question about amino acid composition of proteins: Are there proteins in animals that are made up only from a small subset of amino acids? So instead of all 20 amino acids let's say only 6-14 ( or any arbitrarily small subset) amino acids…
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What Proteins Are Universal To All Life Forms?

According to National Geographic, there are 23 proteins that are common to all life forms: All species in all three domains share 23 universal proteins, though the proteins' DNA sequences—instructions written in the As, Cs, Gs, and Ts of DNA…
Dale
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What are the various types of protein-protein interactions

I understand there are a number of protein-protein interactions, but what types of interactions exist? and what are the characteristics of them?
harpalss
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About the formation of protein

There is a question in my textbook which asks: "What does the glucose produced from photosynthesis form?" However one of the answers said that glucose forms protein. But I'm quite sure that amino acids form protein, don't they? I would be grateful…
david
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Do we understand how (some) proteins work?

Are there proteins whose operation we can describe from first principles using chemistry or physics? I've had introductory college courses in biology, and some classes in neuroscience, so I know that the behavior or purpose of many proteins is well…
adam.baker
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Would this be called a complex?

When an intermediate is formed between a substrate and an enzyme, this is called an enzyme-substrate complex. When a molecule is bound to its respective transfer protein, (the molecule being transported is unchanged when released from the protein at…
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Do these things contain amylase?

I have 10 samples of some food or other things and I need to know, if it contains amylase. I already ran an experiment with storch and iodine, but I have to make it right and my experiment must not be right. List of samples: Saliva (I know this…
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