What's the best method of measuring the number of protein's lysine groups?
438258
Biotinylation\n\nThe highly specific interaction of avidin with the small vitamin biotin can be a useful tool in assay systems designed to detect and target biological analytes. The extraordinary affinity of avidin for biotin allows biotin-containing molecules in a complex mixture to be discretely bound with avidin conjugates.
1137561
http://www.pnas.org/cgi/content/full/102/19/7014
180398
It varies depending whether you want the final product as an active protein or denatured.\n\nFrom cells\n\nHomogenisation\nCentrifugation (assuming you know what fraction the protein will be in)\n\nYou could then possibley use centrifugation across a glucose gradient that would further separate proteins or more simpley...\n\nFind a pH or temperature where the protein is insoluble. (Extremes will denature the protein)\nor...\nUse a size exclusion coloumn to filter out larger smaller proteins (depending on the coloumns specifications and your needs, won't denature).\n\nFor further purification:\n\nUse isoelectric focusing across a gel.\nUse a affinity chromatography coloumn specific to your protein.\n\nHope that helps. It's from memory and should be ok, I study biochemistry so if I've things wrong then I should be quite worried!
40328
Proteins, including enzymes.
60202
Codons are 3 nucleic acids together. Any 3 possible combinations, giving 64 possible combinations.\n\nCodons code a single amino acid, and usually theres a lot in a row. This lets DNA make complex proteins that are made of many codons (amino acids) in a row.
721414
Proteins were precipitated with an equal volume of 20% (w/v) trichloroacetic acid and washed three times with 4 ml of an ethanol/ethyl acetate mixture (1:1). Washings were achieved by mechanical disruption of pellets in the washing solution using a small spatula, and re-pelleting by centrifugation at 6000 g for 5 min. Finally, the precipitates were dissolved in 6 M-guanidine-HCl solution.Ref:Cell. Biochem. Func.(2006)24:79-85.
885040
the building blocks of protein
502057
"C" proteins is the correct answer.
849528
In order to perform in vitro analyses, a protein must be purified away from other cellular components. This process usually begins with cell lysis, in which a cell's membrane is disrupted and its internal contents released into a solution known as a crude lysate. The resulting mixture can be purified using ultracentrifugation, which fractionates the various cellular components into fractions containing soluble proteins; membrane lipids and proteins; cellular organelles, and nucleic acids. Precipitation by a method known as salting out can concentrate the proteins from this lysate. Various types of chromatography are then used to isolate the protein or proteins of interest based on properties such as molecular weight, net charge and binding affinity. The level of purification can be monitored using gel electrophoresis if the desired protein's molecular weight is known, by spectroscopy if the protein has distinguishable spectroscopic features, or by enzyme assays if the protein has enzymatic activity.\n\nFor natural proteins, a series of purification steps may be necessary to obtain protein sufficiently pure for laboratory applications. To simplify this process, genetic engineering is often used to add chemical features to proteins that make them easier to purify without affecting their structure or activity. Here, a "tag" consisting of a specific amino acid sequence, often a series of histidine residues (a "His-tag"), is attached to one terminus of the protein. As a result, when the lysate is passed over a chromatography column containing nickel, the histidine residues ligate the nickel and attach to the column while the untagged components of the lysate pass unimpeded.\n\n\n[edit] Cellular localization\n \nProteins in different cellular compartments and structures tagged with green fluorescent protein.The study of proteins in vivo is often concerned with the synthesis and localization of the protein within the cell. Although many intracellular proteins are synthesized in the cytoplasm and membrane-bound or secreted proteins in the endoplasmic reticulum, the specifics of how proteins are targeted to specific organelles or cellular structures is often unclear. A useful technique for assessing cellular localization uses genetic engineering to express in a cell a fusion protein or chimera consisting of the natural protein of interest linked to a "reporter" such as green fluorescent protein (GFP). The fused protein's position within the cell can be cleanly and efficiently visualized using microscopy, as shown in the figure opposite.\n\nThrough another genetic engineering application known as site-directed mutagenesis, researchers can alter the protein sequence and hence its structure, cellular localization, and susceptibility to regulation, which can be followed in vivo by GFP tagging or in vitro by enzyme kinetics and binding studies.\n\n\n[edit] Proteomics and bioinformatics\nMain articles: Proteomics and Bioinformatics\nThe total complement of proteins present in a cell or cell type is known as its proteome, and the study of such large-scale data sets defines the field of proteomics, named by analogy to the related field of genomics. Key experimental techniques in proteomics include protein microarrays, which allow the detection of the relative levels of a large number of proteins present in a cell, and two-hybrid screening, which allows the systematic exploration of protein-protein interactions. The total complement of biologically possible such interactions is known as the interactome. A systematic attempt to determine the structures of proteins representing every possible fold is known as structural genomics.\n\nThe large amount of genomic and proteomic data available for a variety of organisms, including the human genome, allows researchers to efficiently identify homologous proteins in distantly related organisms by sequence alignment. Sequence profiling tools can perform more speci
1034608
Amino acid is One of the 20 building blocks of protein. The sequence of amino acids in a protein and, hence, the function of that protein are determined by the genetic code in the DNA. \n\nAmino acids are molecules that (in technical terms) contain a basic amino (NH2) group, an acidic carboxyl (COOH) group and a side chain attached to an alpha carbon atom. \n\nThe 20 amino acids are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, and valine. \n\nMost dietitians say it is unhealthy for people but it depends on blood count and things like that you should ask you physician or doctor before you do anything
948762
In proteins and peptides the nitrogen group is reacted with the carboxylic group beside it, with only the very last (or very first) amino acid in the protein/peptide chain being free, where as in amino acids all of the amine groups are free.
77974
Dansyl and dabsyl chloride are used to detect and quantify amino acids.\n\nA series of more specific reagents are used to detect and quantify amino acids. They are 1-fluoro-2,4-dinitrobenzene, fluorescamine, dansyl chloride, \nand dabsyl chloride.\n\n They all react with the amino group of the amino acid, forming a complex that retains the amino acid side chain. Therefore, they will all be different, and we will be able to distinguish them because they will have different physical proeperties. Since they have several conjugated aromatic rings, they are either highly coloured or fluorecent, which allows to determine their concentrations even if we have minute ammounts. Furthermore, the complexes are very stable to the normal conditions of peptide digestion (6M HCl, heat).
419348
There are twenty standard amino acids:\nhttp://www.chemie.fu-berlin.de/chemistry/bio/amino-acids_en.html\nBut there are also two other non-standard amino acids:\nhttp://en.wikipedia.org/wiki/Amino_acid
3494
Not yet, but you can use BLAST to look up information about a DNA or protein amino acid sequence.
4139
Whey protein is one of the highest quality proteins.  Protein quality is measured based on the amino acid composition of the protein in comparison with the amino acid proportions the body needs.  Egg is generally considered to have a quality of 100%, and some lecture notes I was given for my med school biochem class put whey protein at second best at about 93%.
209909
try\nhttp://web.indstate.edu/thcme/mwking/amino-acids.html
527995
Particles, Amino acids (compounds), Proteins, Cells is as specific as I can get.  Seems this question is incomplete.