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

learn more… | top users | synonyms

2
votes
1answer
106 views

How long does a tan last?

How long do melanocytes and melanosomes continue to protect DNA after UV exposure? Basically, if skin is tanned, then over the next month it is shed, will melanocytes continue to produce high levels ...
2
votes
1answer
77 views

Why glycoproteins are better than non-glycoproteins in fulfilling biological tasks?

I have just an intuition that the carbohydrate part of glycoproteins help them to fulfil those tasks like in plasma membranes. You can also get many more receptors if you can use carbohydrates too. ...
2
votes
1answer
202 views

Are Bovine serum albumin, Avidin, Ficoll-70 and Dextran-70 positively charged or negatively charged? [closed]

Bovine serum albumin, Avidin, Ficoll-70 and Dextran-70,are they positively charged or negatively charged ? And which other solvents can be used as a substitute to water for preparing solutions in each ...
2
votes
1answer
29 views

Protein Conformation Modeling

I'm interested in learning about computational modeling in biophysics. I have heard some amount about people modeling proteins as a network of ideal springs to examine things like conformation ...
2
votes
1answer
27 views

Evolutionary rationale behind migration proteins

Tumor cells are able to migrate due to specific migration proteins. What is their evolutionary origin? Or are they simply deregulated?
2
votes
1answer
36 views

Epistasis when interacting loci are codons within a single gene

There is epistasis when the effect on the phenotype of one gene is influenced by one or more other genes (called modifiers). Is there a similar concept when the effect on the phenotype of one site ...
2
votes
3answers
95 views

Bacterial cell lysis buffer used in proteomics procedures

What kinds of detergent-free bacterial lysis buffers exist? The proteins we're extracting will be later analyzed by LC-MS/MS, and we're looking for a lysis buffer that won't interfere with this ...
2
votes
1answer
54 views

PTMs of proteins via mass spec?

I understand that mass spec is widely used to study PTMs like glycosylation of proteins, but how can mass spec determine correct PTM structure of say glycosylation if two glycan structures have the ...
2
votes
1answer
309 views

Where to put the gene after eukaryotic promoter for best expression levels?

As far as I know there is an optimum distance between a promoter and the gene for the best expression levels. What is that distance for common promoters like CMV, SV40? If you have a first hand ...
2
votes
1answer
28 views

The use of proteins in memory creation

I have very limited knowledge of how the human memory works as I think, at this time, most people do. However, I have been reading and some articles which say, and I quote the article just linked ...
2
votes
0answers
41 views

Circular mRNA to produce long proteins

Ribosomes can read mRNA and produce proteins, if we somehow make a circular mRNA for the ribosome to bind onto, it will make infinitely long "proteins", (since ribosomes can make very big proteins, I ...
2
votes
0answers
41 views

Removal of the Initial Methionine in Venus for FRET

I'm working on building some FRET reporters. In addition to a cleavage site (of varying composition from 15-18AA), a 1 AA linker, I'm using Venus and Cerulean. Initially I was worried that 18AA ...
2
votes
1answer
43 views

How do you differentiate between SR protein and SR-like protein?

What are the criteria that the researchers use to choose whether a protein is an SR protein or and SR-like protein?
2
votes
0answers
46 views

How to use mechanical microstrainer to extract tissue proteins from human?

Background: There are many methods to extract proteins form human tissues out there. The majority of them use an extraction buffer containing variable concentrations of detergents and protease ...
2
votes
0answers
38 views

Endocannabinoid Transporters - which ones are Likely to Exist and what is the Evidence for their Respective Existence?

Endocananbinoid = Endogenous Cannabinoid or CB1 and CB2 ligands. I'm asking which endocannabinoid transporters exist and could the one answering show all the evidence for the existence of the ...
2
votes
0answers
193 views

What specifically allows alpha-complementation in beta-galactosidase?

I'm familiar with the use of alpha-complementation of beta-galactosidase with the pUC alpha-peptide and the M15 lacZ gene product, and would like to hypothetically apply alpha-complementation in other ...
2
votes
0answers
57 views

Are there examples of PTMs that add different chemical groups (and mass) to different amino acids?

I'm talking about this type of post-translational modifications. What I'm interested in is not whether some modifications can only occur on specific amino acids (that's clear), but if the nomenclature ...
1
vote
2answers
285 views

How are proteins formed?

Somewhere, I have read that we need to consume proteins to make amino acids to make new proteins. What does it suggest? How do we make proteins from proteins?
1
vote
4answers
67 views

Which point mutations in proteins are OK, and which cause significant change?

I heard that some point mutations in proteins are OK, like from alanine to glycine (I'm not sure, it's just an example), some will change the protein significantly. I want to understand deeper but ...
1
vote
2answers
73 views

Conserved proteins are non immunogenic

I read that proteins that have been highly conserved are non-immunogenic. Why is it so ? What is the special thing that makes it non immunogenic(antibodies against them are hard to make) ?
1
vote
1answer
114 views

What type of mutation causes Progeria?

I'm doing my High School biology final on Progeria, and am wondering what type of mutation causes this disease. I know that the LMNA gene codes for the "prelamin A" protein, and that protein contains ...
1
vote
2answers
276 views

PEG-silane treatment: why incubate for 18 hours at 60 degrees Celsius?

I am conducting a biochemistry-related experiment and I have been unable to understand a step which is commonly performed. My aim in this step is to apply a PEG (Polyethylene glycol) silane layer. ...
1
vote
1answer
185 views

Which concentration of BSA is recommended for dynamic light scattering experiments?

What is the recommended concentration of BSA to be mixed with water so as to prepare a very dilute solution in order to clearly study the intensity-intensity correlation with single scattering ? I ...
1
vote
1answer
19 views

Formation of peptide bond..?

Proteins peptide bond is made by condensation process in which a molecule of water is released and according to this process it is not favorable in water systems than how peptide bond is formed by ...
1
vote
1answer
13 views

What does the term 'modified residue position' in phosphorylation mean?

Does it mean the position of the amino acid in the protein sequence, or something else? For example, I came across the phrase "S 368 phosphoryation" where S is the modified residue and 368 is the ...
1
vote
1answer
27 views

How are cyclic hormones characterized?

I have a question regarding the description of a subset of peptide hormones, called cyclic hormones. Two examples of cyclic hormones would be somatostatin and melanin-concentrating hormones. I know ...
1
vote
1answer
29 views

Staphylococcus AG structure?

I found this statement in my study materials in the section of Staphylococcus The AG structure: protein AG (species specific); polysaccharide AG (serotype specific). I know what is ...
1
vote
1answer
130 views

Codon alignment via Python? [closed]

I have pairs of coding DNA sequences which I wish to perform pairwise codon alignments via Python, I have "half completed" the process. So far.. I retrive pairs of orthologous DNA sequences from ...
1
vote
1answer
575 views

What is the difference between average and monoisotopic mass calculations of peptides?

I often have to calculate the mass of peptide sequences using calculators such as here. I have the option of calculating the average and monoisotopic mass, but what is the difference?
1
vote
1answer
111 views

What can cause the swelling in high protein diet of Whey proteins?

I am thinking what can cause the swelling of high protein diet of Whey proteins. Liver does breaks those proteins to branched chain amino acids (BCAA), which can cause this swelling. However, I am ...
1
vote
1answer
46 views

How to parse SCOP parseable files PDB residue identifiers?

I am trying to parse the SCOP parseable files, specifically dir.des.scop.txt ver 1.75. But, I have been facing problems with the PDB residue identifiers in the file. This is a tab limited file and the ...
1
vote
1answer
58 views

Topology of protein

The domain structure of protein Z, which is composed of 180 amino acids, is shown in the upper part of the figure below. Protein Z is palmitoylated at a cysteine residue (the third amino acid) ...
1
vote
1answer
155 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 ...
1
vote
1answer
47 views

Dimethyltryptamine binding site on Sigma 1 type opioid receptor?

I asked this question Dimethyltryptamine and Sigma 1-type opioid receptor interaction but it seems that I didn't express myself well. I was looking for the place on Sigma 1 type opioid receptor where ...
1
vote
1answer
84 views

What are the characteristics of a promising drug target?

When researchers are looking to start developing a drug, what characteristics do they look for in the potential proteins (assuming they already have good quality structural models)?
1
vote
1answer
53 views

What I can do in order to improve the folding of the protein?

I am struggling with the expression of the certain protein. It seems that it is not properly folded and thus, it is not active. I tried to express it at the lower temperature and for the longer time, ...
1
vote
1answer
35 views

conservation of C-peptide sequence in the guinea pig

Where can I compare the C-peptide sequence of guinea pig with human or mouse? I am also interested in finding whether the guinea pig has insulin 1 and 2 to know whether I could use an anti-C-peptide 1 ...
1
vote
1answer
25 views

fibrinogens and fibrins - are they the same molecule?

Some proteins are "activated", like fibrinogens; they are turned into fibrins by thrombins, and then the fibrins can aid in blood clotting. Are fibrinogens and fibrins the same molecule, just in ...
1
vote
1answer
30 views

Vesicular and non vesicular transport

I have to classify them either as transported in vesicles or without vesicles. What I think - Non-vesicular 2.vesicular 3.vesicular 4.vesicular 5.non-vesicular 6.vesicular 7.vesicular ...
1
vote
1answer
35 views

Removing Sugars Bound to a Protein

I recently purchased some Maltose Binding Protein and as the name suggests this protein binds to maltose. The problem I have is the protein arrive with maltose bound. I know this through native mass ...
1
vote
1answer
46 views

Protein Structure Statistics [closed]

Could you show me references of any works you know of where, 1- they take all the known protein structure data (that is the coordinate data of all the proteins in PDB database lets say or elsewhere) ...
1
vote
1answer
146 views

How do proteins get into the blood stream?

So I'm asking this in reference to the injection of insulin, which is commonly done subcutaneously (in the hypodermis, a fatty part of skin). Now I know proteins usually get into the blood when ...
1
vote
1answer
52 views

Dimethyltryptamine and Sigma 1-type opioid receptor interaction

Where exactly do dimethyltryptamine and sigma 1-type opioid receptor interact? I read in this When the Endogenous Hallucinogenic Trace Amine N,N-Dimethyltryptamine Meets the Sigma-1 Receptor but it ...
1
vote
1answer
40 views

Enzymatic Protein Deglycosylation of TCL

I've done O- and N- linked enzymatic deglycosylation of purified and lyophilized proteins. Following some modifications to the manufacture's protocol, I had great results. I now want a student to ...
1
vote
1answer
89 views

Which is the correct statement on proteins?

I need help with one of the questions on my biochemistry assignment Choose the correct statement on proteins: a) proteins are folded by alpha-helix b) proteins can preserve their function even if ...
1
vote
1answer
107 views

DNA Replication

I just wanted to understand the basic steps behind the replication of the lagging strand of DNA: Have helicase unwind it first DNA Primase lays down RNA primers in fragments, called Okazaki ...
1
vote
1answer
1k views

How difficult is to renature a protein?

I know of Anfinsen's experiments and I'm aware that some denatured enzymes may regain their lost activity through the removal of the denaturant agent. What I'm unaware of is how rare is it for a ...
1
vote
0answers
19 views

Can a protein be present in a protein-based complex but not important for the function of the complex

Suppose protein A is present in a protein complex ABC. Is it possible that protein A is actually is not important for the function of protein complex ABC? Or put alternatively, can a protein X not ...
1
vote
0answers
23 views

Planar circular DNA and protein

I am trying to develop a planar (two dimensional) lattice based framework to simulate ring (circular) DNA and proteins. To verify my model, I need to simulate real DNA and proteins. The base idea for ...
1
vote
1answer
27 views

If a gene altered causes cancer and creates a protein for cancer can the new protein be isolated in some way?

In the above title question, can the protein thats altered not be isolated (to separate out from other proteins) somehow? Is there nothing that can bind to the specific cancer proteins that will not ...