Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [proteins]

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

2
votes
1answer
65 views

How does radiolabeling work?

Protein turnover can be measured by calculating the "decay" or loss of radio-labeled proteins in the blood, for example, but I am confused at how this calculation works. Wouldn't the radioactive ...
1
vote
0answers
41 views

Is osteoid an uncalcified substance?

I recently learned about Osteoid (the substance secreted by osteoblasts during intramembranous ossification), and I read that it was an "unmineralized organic component of bone." Now, does this mean ...
6
votes
2answers
138 views

How do membrane proteins find their target locations?

The question might be asked for any kind of "bound" proteins, but I'd like to restrict it to membrane proteins. Assuming membrane proteins (or their main parts) don't (or aren't) build in situ but at ...
2
votes
1answer
47 views

Protein molar mass from Uniprot ID?

I have a long list of uniprot IDs. How can I get the mass of the "canonical" isoform for each? Ideally from some Python library.
3
votes
0answers
175 views

Plant vs animal protein digestibility?

The protein scoring methodologies ( https://en.wikipedia.org/wiki/Protein_Digestibility_Corrected_Amino_Acid_Score) rate plant proteins of a lower quality than animal proteins. Now I can understand ...
0
votes
1answer
417 views

Does pepsin digest plant protein?

This may sound trivial, but... Protein is sourced from plants and animals. Pepsin and HCl digest meat (animal protein). Does pepsin also digest plant-based proteins? I took a look at few articles ...
1
vote
1answer
81 views

Since the matter in the brain is recycled every few days how does consciousnesses work?

Since parts of the brain are recycled every few days does that mean that materialistic theories of consciousness don't work?
1
vote
1answer
458 views

Life cycle of proteins

I try to get a picture of the life cycle of a protein (considered as a specific molecule). This is how I can imagine it: After the cell is born a protein molecule is synthesized by gene expression ...
0
votes
1answer
37 views

Can proteins structure change depending of alimentation of an organism? [closed]

In my understanding protein are built using information caring by RNA. So a given protein should always have the same structure in a given organism has the DNA of this organism does not change. I'm ...
2
votes
1answer
72 views

Etymology of vimentin [closed]

What is the etymology of the intermediate filament , Vimentin?
0
votes
1answer
180 views

The difference between the beta-sheets and the quaternary structure of proteins

My biochemistry book says that beta-pleated sheets is a form of secondary structure of proteins, and it is formed between two or more polypeptide chains. I wonder why the sentence in bold doesn't ...
3
votes
1answer
58 views

What do you call mRNAs that translate to the same protein?

For example AUAACC and AUCACG in distinct mRNAs may both be translated to the same dipeptide Ile-Thr.
3
votes
1answer
132 views

How can carnitine enter the mitochondrial matrix without OCTN2?

Some people have defects on the gene SLC22A5, giving them problems with their OCTN2 transport protein (Organic cation transport). OCTN2 transports carnitine into the mitochondial matrix where it can ...
0
votes
0answers
43 views

Protein Purification - what I should do if I used the mixed up the buffer?

I'm purifying a protein , and I used the following methods 1- Immobilized ion exchange chromatography (using HisTrap FF column) to remove His-tag 2- add ULP1 (protase) + DDT to cleavege sumo tag 3-...
1
vote
2answers
137 views

What are some examples of non-homologous sequences having similar functions?

I am trying to find some proteins that are non-homologous but functionally similar. However, I cannot seem to find concrete examples. Can someone please point out any resources or provide examples?
3
votes
1answer
347 views

Are proteins a different shape in space?

Is the shape of a protein affected by gravity? In space, will the shape of a protein be different to what it is on Earth? If the structure and shape is in fact affected, then would it be enough of a ...
0
votes
0answers
23 views

What is differential enzyme inhibition?

My textbook says that differential enzyme inhibition is useful for clinical applications, such as acid phosphatase. But I don't understand why, or how their differential activity can be measured.
2
votes
0answers
50 views

What attaches plant cells to the cell wall?

In animal cells integrins span the plasma membrane and attach the cell membrane to the extracellular matrix. I was wondering how are plant cells attached to the cell wall? Is it just the middle ...
-1
votes
1answer
74 views

The insulin protein of apes & chimpanzees [closed]

How many amino acids do the insulin protein of apes and chimanpzees compose of?!
0
votes
0answers
20 views

Extrapolate FRET result to molecule transfer

How would a FRET result translate into transporting molecules? For example, if you had two proteins close together and a FRET result showed positive in that region, how could we extrapolate that ...
0
votes
1answer
30 views

Can you say “screening for a” in English?

I know this is not a "Correct Use of English Forum" but I'm afraid that people from outside the field won't be able to properly answer my question. Would it be correct to say "screening for a long ...
2
votes
0answers
36 views

Do GPCRs have 7TMHs?

I've screened a non-redundant set of GPCRs acquired from UniProt. I found a handful of examples of record IDs that contain more than the 7 TMHs. For example Q89609 and P20905, both of which have been ...
1
vote
0answers
32 views

Indicators of Ras binding domain (RBD) activity in Ras effector proteins?

Ras family based small GTPase proteins usually have a Ras binding domain (RBD) in their effector downstream proteins like Raf. Roughly Ras proteins cycle between active(GTP-bound situation) and ...
2
votes
1answer
49 views

How big is the change in proteins due to alternative splicing?

How different can the proteins be that are coded from the same DNA-sequence but undergoe alternative splicing? What I am trying to wrap my head around is why we are so fixated with the DNA-sequences ...
1
vote
0answers
55 views

Visual maps of the neuronal membrane

There are lots of visual maps of the brain as a whole, especially the cortex, that show the distribution of "features" over a two-dimensional map, e.g. the Brodman areas (their morphology and their ...
0
votes
1answer
26 views

Will a sandwich assay work with a GST 26 antibody/protein?

I have a GST 26 kda antibody, and want to use it in a sandwich lateral flow assay. Are there enough epitope regions for both antibodies to bind to the protein?
1
vote
0answers
33 views

Can one refer to pieces of proteins produced by enzymatic digestion as “enzymatic lysates”?

A Russian text I'm translating says this: The location of post-translational modification (PTM) sites was determined using the “bottom-up” approach commonly used in this field. In accordance with ...
3
votes
2answers
415 views

What is the function of cystine, cysteine, and cysteine protease?

I am not a biologist, and I have a probably dumb biological question. For some purpose, I need to understand the function of the CTNS gene, and here is the definition of it: "This gene encodes a ...
0
votes
2answers
37 views

Will a polyclonal antibody attach to proteins of different kDA?

If I have a GST 26kDa polyclonal antibody, will it bind to the GST 28kDa protein as well?
-3
votes
2answers
1k views

Where on an amino acid does it attach to the protein backbone? [closed]

I've been trying to find conclusive information regarding where within an amino acid (AA) it attaches to the protein backbone (PBB). I know that, coming off of the PBB, the AA side chain is connected ...
1
vote
0answers
21 views

Multi-protein drug treatments

Apologies if this an obvious question - I am very new to this. I am, as of now, under the impression that multiple SNP variations interact to create multiple mutated proteins, which ultimately results ...
0
votes
0answers
264 views

What are the causes of abortive initiation?

I was reading more about DNA transcription, and it mentioned abortive initiation. The article gave no explanation as to why the phenomenon occurs. The only explanation I can think of is that it is ...
2
votes
4answers
76 views

Why do food items expire?

Why do food items and medicines expire after sometime?
4
votes
1answer
557 views

Effect of mutation on phenotype

Is there a type of mutation that changes the phenotype of an organism, but not the protein sequence?
2
votes
2answers
91 views

Is there a hypernym for enzymes that “cut” other molecules?

I have searched on Google for a hypernym/umbrella term that encompasses all enzymes whose function is to cut other molecules, but I have yet to find such a term. The term I am looking for would ...
3
votes
1answer
664 views

What is the distinction between deoxyribonucleases and restriction enzymes?

Both deoxyribonucleases (DNases) and restriction enzymes are endonucleases (some DNases can be exonucleases). They both break the bonds between nucleotides. Therefore, what is the difference between ...
0
votes
1answer
512 views

Pros and cons of amino acid structure vs DNA sequences for evolutionary comparison [closed]

This is an analysis question for a lab on the amino acid differences in beta globin amongst different primates, and using such differences to construct a cladogram and infer evolutionary relationships ...
1
vote
1answer
102 views

Why do humans cook animal meat

Why do humans "need" to cook animal meat? It seems there's an aspect of safety to it: are other animals (eg, house cats, dogs) not vulnerable to the same diseases we get from modern food processing ...
0
votes
1answer
32 views

Can a protein go outside of nucleus after go inside with nuclear localization signal (NLS)

To make a protein (for example Cas9, GFP...) able to enter the nucleus, we need to add a NLS tag for it. So will it able to go outside the nucleus after get inside ?
5
votes
1answer
75 views

Does cocaine bind competitively or non competitively to DAT?

I was just wondering whether cocaine, once reaching a synapse, binds to a DAT (Dopamine transporter) competitively or non competitively, or neither of them?
8
votes
2answers
430 views

Why do fully grown organisms need protein intake?

If proteins are building blocks of an organism then it makes sense why a growing organism would need an intake of them, but why would a fully grown organism need proteins (aside from those lost by ...
2
votes
1answer
125 views

In myosin II are regulatory and essential light chains calcium binding proteins or sites of phosphorylation?

According to my medical physiology by Rhodes and Bell their description is as follows: the essential light chain is necessary for myosin stability, and the other chain called the regulatory light ...
8
votes
2answers
704 views

How does hypochlorous acid inactivate viruses?

I was reading how bleach was used very widely as a disinfecting agent during the 2014 West Africa ebola outbreak and am interested in the mechanisms with which hypochlorous acid inactivates viruses. ...
2
votes
0answers
31 views

To which SCOP Class corresponds the following secondary structure?

I need to classify this protein into one of the SCOP class (all $\alpha$, all $\beta$, $\alpha +\beta$, $\alpha/\beta$, or small protein). I'm having difficulties understanding the difference ...
5
votes
1answer
7k views

Do proteins generally contain phosphorus and sulfur?

I've heard that proteins generally contain six main elements - carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur. I know that proteins are made from amino acids. Amino acids are composed of ...
2
votes
1answer
76 views

Does terminology for changes in membrane potential refer to additive or multiplicative change?

Is the membrane potential just the number of mV, or is it to what extent it differs from 0? For example: If the mV goes from -40 to -60, can you say that: The membrane potential decreases, because ...
3
votes
1answer
125 views

Kidney failure → Inhibition of Na+/K+ pump → Heart failure

I read in my biology book: Due to kidney failure, the concentration of K+ in the body increases. This can lead to heart failure too. But there wasn't any explanation to the mechanism of this ...
4
votes
3answers
325 views

Why do bacteria eat enamel?

What causes tooth decay bacteria or acids? I've been told that it is a combination of both but why would bacteria eat enamel? There are much easier supplies of protein for bacteria to munch through (...
3
votes
2answers
242 views

Dissolving cell pellet after sonication

I was doing a protein prep and I made a mistake. After sonicating my cells, I was supposed to centrifuge and collect the supernatant (my protein is soluble and comes in the supernatant). I however, ...
5
votes
2answers
3k views

Why are proteins always made in N to C direction?​

Why are proteins always synthesized from the N-terminus to the C-terminus? Can there be any “reverse” peptide-bond formation to synthesize proteins in the C-terminal to the N-terminal direction?