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

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What happen's to a virus's capsid after it injects its genetic material into the host cell?

After a virus (one of the varieties which infects the cell via injection and not endocytosis) injects its genetic material into the host cell, what happens to its protein coat? I would guess that it ...
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2answers
305 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?
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1answer
30 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 ...
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1answer
227 views

What do the Clustal Alignment Symbols Mean?

Occasionally I will run protein alignments on peptide families and I can never remember what the symbols mean to show degrees of identity. What do they mean?
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1answer
81 views

Selective Androgen Receptor Agonist

I'm looking for an inducer that strongly activates the androgen receptor, but not the glucocorticoid receptor that is not DEA regulated. I know that SARMS (Selective Androgen Receptor Modulators) are ...
3
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1answer
45 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 ...
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1answer
114 views

Color van der waals bonds in swiss PdbViewer

I'm trying to color certain amino acid's van der waals bonds as in the following picture: can anybody please describe the steps to accomplish that?
2
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1answer
301 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 ...
3
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1answer
150 views

How to wash the column during protein purification with GST tag?

I have been working with GST tagged proteins for the last 4 years and after loading the cell lysate into the column I was washing it with 20-30 column volumes of PBS and sometimes my proteins were ...
2
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1answer
36 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
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1answer
37 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 ...
0
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1answer
58 views

Curious about Brazzein

What is in compound "Brazzein" that it makes it 2000 times more sweeter than sugar? Can anyone please explain the science behind it?
2
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2answers
281 views

What are the functions of disulphide bonds?

What are the functions of disulphide bonds between amino acids in proteins or peptides?
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1answer
44 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 ...
2
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1answer
471 views

What is optical density in Lowry's protein estimation method?

I have a few questions: What is an OD value? Why do we use blank solution in Lowry's protein estimation method? If The OD of a protein is 0.01, what does it mean? Thanks in advance.
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1answer
27 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 ...
8
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1answer
884 views

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 ...
2
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1answer
2k views

Why do three nucleotides code for one amino acid? Why not 5 nucleotides? [duplicate]

We all know why there are 3-base codons, and why there aren't any 2-base codons. But why is there not a 4-base a 5-base codon?
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2answers
83 views

Can protein precipitate out in alcohol during DNA extraction?

In common lab sessions to extract DNA from strawberry or cheek cells, will there be protein contaminating the DNA extract in alcohol? If so, how can we prevent protein from precipitating out of the ...
3
votes
1answer
86 views

Function of heparin and dextran sulfate for removing proteins

From this article : The reaction was terminated and the histones, and most nonhistones, were removed by adding the nuclease-treated chromosomes to a solution containing dextran sulfate (2 ...
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1answer
43 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 ...
2
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1answer
123 views

how do they identify different protein chains?

Can someone please explain how different protein chains occur exactly? I'm not talking about the side chain, but the protein chain which is typically labelled as A,B,C etc in the PDB. I'm curious as ...
2
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2answers
224 views

pI and pH relationship in context of ion exchange protein purification

I am confused about relationship between isoelectric point and pH in context of ion exchange protein purification. Why we cannot use this method for protein with pI below 7? Thank you very much for ...
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2answers
114 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) ?
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1answer
80 views

Length differences between physically interacting proteins

What can be said on the length differences between interacting proteins? Are they usually of similar sequence lengths or not at all?
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1answer
78 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 ...
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3answers
231 views

What are some examples of genes that code for multiple proteins?

The title pretty much says it all. It is widely taught that a gene in a eukaryotic system could produce more than one protein due to post-transcriptional modification, but I do not believe I have come ...
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1answer
69 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 ...
2
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1answer
49 views

Does Sirtuin protein family Sir2 work in low-calorie diet mostly?

I am reading about the protein family in relation to the prolongation of cell life. It is known that Sirtuins have been implicated in influencing a wide range of cellular processes like ageing, ...
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1answer
35 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 ...
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1answer
41 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 ...
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2answers
11k views

Calculating Protein Concentration from Kilo Units (KU)

I am looking to purchase Pyruvate Kinase from the Sigma Website, they state the volume in Kilo Units (KU) i.e. 1, 5 or 25 KU. It also states there are 350-600 units / mg protein. Does this mean one ...
3
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2answers
64 views

Why are genes expressed as proteins rather than other types of bio-molecules?

I guess, we could infer that the structure of an amino acid has the same functional units as RNA is used to synthesise it. Therefore, from a logical point of view it would make sense that genes are ...
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1answer
90 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) ...
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1answer
52 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 ...
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1answer
205 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 ...
3
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1answer
104 views

What is the translation termination efficiency in mammalian cells?

When I express proteins in bacteria I put at least two stop codons at the end of the gene to increase the termination efficiency. Is this the case in eukaryotic cells too? If I put a single stop codon ...
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2answers
870 views

More proteins from diet when common cold and flu?

My coach says that I need to eat 1.2 - 1.5 grams of proteins per kilogram when I have a common cold and flu. I normally eat one gram of proteins per kilogram, while double it when doing my exercise ...
2
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1answer
784 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 ...
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1answer
331 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 ...
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0answers
531 views

Rosetta ab initio prediction and protein-protein interaction fitness help [closed]

I have designed several proteins which I predict have interactions with another protein using the sequence based Conjoint Triad Method. I would like to know which ones structurally are predicted to ...
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1answer
291 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 ...
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1answer
172 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 ...
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0answers
266 views

Statistical Coupling Analysis (SCA) to identify coevolved residues: use of ICA [closed]

We've begun to try out the SCA Matlab toolbox (latest version) downloaded from Dr. Rama Ranganathan's website, and, following the included tutorials, would like to apply it to our protein family. The ...
2
votes
3answers
242 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 ...
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1answer
56 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 ...
3
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1answer
252 views

Western blotting questions?

everyone. I've just been introduced to the procedure of Western blotting from my reading, though I'm not entirely sure about some points. I'd appreciate it if someone could help me with this. What ...
4
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1answer
156 views

Why are transmembrane proteins difficult to crystallise?

I know that in vivo there are a lot fewer transmembranous proteins in general, and that they are produced at a lower rate than their free counterparts. This is mainly because transmembrane proteins ...
2
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1answer
84 views

How to identify active protein in a complex mixture?

I am trying to figure out how to identify which protein in a complex mixture is producing a certain effect. There is an assay for the effect, so anything (a fraction of the mixture) can be tested ...