Proteins in foods may be modified to increase their nutritional qualities.

Proteins in legumes and cereals may be transformed to provide the amino acids needed by human beings for a balanced diet.

Proteins that bind to either the 3 ' or 5 ' UTR may affect translation by influencing the ribosome's ability to bind to the mRNA.

Proteins that are needed in a particular region of the cell can also be translated there ; in such a case, the 3 ' UTR may contain sequences that allow the transcript to be localized to this region for translation.

Proteins may be purified from other cellular components using a variety of techniques such as ultracentrifugation, precipitation, electrophoresis, and chromatography ; the advent of genetic engineering has made possible a number of methods to facilitate purification.

Proteins may be incorporated into the plasma membrane, or either trapped in the periplasm or secreted into the environment, according to whether or not there is an outer membrane.

Proteins may therefore be separated roughly according to size ( and thus molecular weight ); however certain glycoproteins behave anomalously on SDS gels.

Proteins may be classified according to both structural and sequence similarity.

Descriptions of such terms may be found at the CATH Web site the Structural Classification of Proteins ( SCOP ) Web site and a Glaxo-Wellcome tutorial on the Swiss bioinformatics Expasy Web site.

Proteins of very different amino acid sequences may fold into a structure that produces the same active site.

Proteins that lack tryptophan may be coupled to a fluorophore.

Proteins present in the female reproductive tract or on the surface of the ovum may influence which sperm succeeds in fertilizing the egg.

Proteins with many bulky hydrophobic groups may require longer heating periods.

Proteins may exist in several different source databases, and in multiple copies in the same database.

Proteins might interact for a long time to form part of a protein complex, a protein may be carrying another protein ( for example, from cytoplasm to nucleus or vice versa in the case of the nuclear pore importins ), or a protein may interact briefly with another protein just to modify it ( for example, a protein kinase will add a phosphate to a target protein ).

Proteins can also be modified to include non-peptide components, such as saccharide chains and lipids.

Proteins can, thus, be separated according to their isoelectric point ( overall charge ) on a polyacrylamide gel using a technique called isoelectric focusing, which uses a pH gradient to separate proteins.

Proteins can be informally divided into three main classes, which correlate with typical tertiary structures: globular proteins, fibrous proteins, and membrane proteins.

Proteins are the chief actors within the cell, said to be carrying out the duties specified by the information encoded in genes.

Proteins can also bind to, or even be integrated into, cell membranes.

Proteins do not have to unfold to be imported into the peroxisome.

Proteins can often be synthesized directly from genes by translating mRNA.

Proteins that are to be targeted to a particular organelle or for secretion have an N-terminal signal peptide that directs the protein to its final destination.

Proteins can be very large molecules with very specific shapes in folds and sheets, etc.

Proteins which are supposed to be expressed at the endoplasmic reticulum are recognised part-way through the translation process.

Proteins produced in the symplast included RXLR proteins, which contain an arginine-X-leucine-arginine ( where X can be any amino acid ) sequence at the amino terminus of the protein.

Proteins can be accurately quantified because the signal generated by the different amounts of proteins on the membranes is measured in a static state, as compared to chemiluminescence, in which light is measured in a dynamic state.

Proteins that have been separated can be cut out of the gel and then analysed by mass spectrometry, which identifies the protein.

Proteins are chemically amides, which can also be hydrolyzed by acid-base catalysis.

Proteins can be detected down to femtomole quantities, well below the detection limit for most assay systems.

Proteins, developed by Genentech of San Francisco, California, were administered to eight rats during the flight while another eight rats accompanying them on the flight did not receive the treatment.

Proteins are separated by charge in agarose because the pores of the gel are too large to sieve proteins.

IGF-1 and IGF-2 are regulated by a family of proteins known as the IGF-Binding Proteins.

Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, which form a system of scaffolding that maintains cell shape.

Proteins can bind to other proteins as well as to small-molecule substrates.

Proteins consist of one or more polypeptides arranged in a biologically functional way and are often bound to cofactors, or other proteins.

* Proteins: consisting of gag proteins, protease ( PR ), pol proteins and env proteins.

Proteins, due to the precise conformations they fold into, are nature's original nanomachines ; developing an inexpensive and practical way to design and target proteins would completely revolutionize medicine and would have incredibly far-reaching implications.

These T3SS-injected proteins are called Yops ( Yersinia Outer Proteins ) and include Yop B / D, which form pores in the host cell membrane and have been linked to cytolysis.

* Orientations of Proteins in Membranes ( OPM ) database 3D structures of integral and peripheral membrane proteins arranged in the lipid bilayer

* Protein Data Bank of Transmembrane Proteins 3D models of all transmembrane proteins currently in PDB.

Proteins with GPI anchors are an exception to this rule and can have purification properties similar to those of integral membrane proteins.

Proteins that contain zinc fingers ( zinc finger proteins ) are classified into several different structural families.

Proteins for the milk replacer come from different sources ; the more favorable and more expensive all milk protein ( e. g. whey protein-a bi product of the cheese industry ) and alternative proteins including soy, animal plasma and wheat gluten.

When examining the chromosomes, Ritossa found a " puffing pattern " that indicated the elevated gene transcription of an unknown protein .< ref name =" pmid9222594 "> This was later described as the " Heat Shock Response " and the proteins were termed the " Heat Shock Proteins " ( Hsps ).

* Nikon MicroscopyU Introduction to Fluorescent Proteins includes a table of molar absorptivity of fluorescent proteins.

Luminal proteins: Proteins found in the lumen of the Golgi complex that need to be transported to the lumen of the ER contain the signal peptide KDEL.