complete protein

Examples of complete protein in the following topics:

• Protein Structure

  • The shape of a protein is critical to its function because it determines whether the protein can interact with other molecules.
  • Protein structures are very complex, and researchers have only very recently been able to easily and quickly determine the structure of complete proteins down to the atomic level.
  • (The techniques used date back to the 1950s, but until recently they were very slow and laborious to use, so complete protein structures were very slow to be solved.)
  • A protein's primary structure is the unique sequence of amino acids in each polypeptide chain that makes up the protein.
  • As a result, quaternary structure only applies to multi-subunit proteins; that is, proteins made from one than one polypeptide chain.

• Regulating Protein Activity and Longevity

  • The addition of methyl groups to a protein can result in protein-protein interactions that allows for transcriptional regulation, response to stress, protein repair, nuclear transport, and even differentiation processes.
  • Methylation in the proteins negates the negative charge on it and increases the hydrophobicity of the protein.
  • The addition of an ubiquitin group to a protein marks that protein for degradation.
  • Ubiquitin acts like a flag indicating that the protein lifespan is complete.
  • These proteins are moved to the proteasome, an organelle that functions to remove proteins to be degraded .

• Mapping Protein-Protein Interactions

  • Mapping protein-protein interactions gives us a better understanding of molecular mechanisms inside the cell.
  • The protein complexes formed could be stable (proteins interact for a prolonged period of time) or transient (proteins interact for a brief period of time).
  • The complete map of protein interactions that can occur in a living organism is called the interactome.
  • The tag serves as a tool to purify the bait protein and associated proteins by affinity chromatography.
  • Principle of the bait and prey method for the study of protein-protein interaction.

• Crystallographic Analysis

  • Electron crystallography has been used to determine some protein structures, most notably membrane proteins and viral capsids.
  • Studies of protein crystallography help determine the three dimensional structure of proteins and analyze their function alone or within multimolecular assemblies.
  • The structure-function analysis is completed by biochemical and biophysical studies in solution.
  • The protocol for completing a successful crystallographic analysis requires production of proteins (cloning, mutagenesis, bacterial culture, etc.), purification of recombinant proteins (such as chromatography of affinity and gel filtration), enzymatic tests and inhibition measurement (spectrophotometry), crystallization, x-rays crystallography and structural analysis, interactions determination (microcalorimetry, fluorescence, BIAcore), conformational analyses (circular dichroism, ultracentrifugation, light scattering), modifications analysis (mass spectrometry), bioinformatics, and molecular modelisation.
  • The Protein Data Bank (PDB) is a freely accessible repository documenting the structures of proteins and other biological macromolecules.

• Nature of the Virion

  • A virion is a complete viral particle consisting of RNA or DNA surrounded by a protein shell, constituting the infective form of a virus.
  • Virion capsids are formed from identical protein subunits called capsomeres.
  • Virally coded protein subunits will self-assemble to form a capsid, in general requiring the presence of the virus genome.
  • Complex viruses code for proteins that assist in the construction of their capsid.
  • Proteins associated with nucleic acid are known as nucleoproteins, and the association of viral capsid proteins with viral nucleic acid is called a nucleocapsid.

• Protein Folding, Modification, and Targeting

  • The native conformation of a protein is a stable three-dimensional structure that strongly determines a protein's biological function.
  • Even if a protein is properly specified by its corresponding mRNA, it could take on a completely dysfunctional shape if abnormal temperature or pH conditions prevent it from folding correctly.
  • The denatured state of the protein does not equate with the unfolding of the protein and randomization of conformation.
  • This protein serves as a channel for chloride ions.
  • A complete understanding of prion diseases awaits new information about how prion protein affects brain function, as well as more detailed structural information about the protein.

• Basic Techniques in Protein Analysis

  • The basic techniques used to analyze proteins are mass spectrometry, x-ray crystallography, NMR, and protein microarrays.
  • The spins of neighboring nuclei interact with each other in ways that provide definitive structural information that can be used to determine complete three-dimensional structures of proteins.
  • Protein microarrays have also been used to study interactions between proteins.
  • One protein of interest is genetically fused to the BD and another protein is fused to the AD.
  • The western blot, or protein immunoblot, is a technique that combines protein electrophoresis and antibodies to detect proteins in a sample.

• Complete Antigens and Haptens

  • Haptens are molecules that create an immune response when attached to proteins.
  • Fluorescein is often conjugated to a protein and this allows scientists to examine the location of the protein using a fluorescent microscope.
  • Antigens may be either complete or incomplete based on the nuances of their molecule structure.
  • A complete antigen is essentially a hapten-carrier adduct.
  • If this happens with enough haptens, there will not be enough antibodies left to bind to the complete antigen, so the antibody response is then inhibited.

• Fluid Mosaic Model

  • For example, myelin contains 18% protein and 76% lipid.
  • Proteins make up the second major component of plasma membranes.
  • Integral proteins (some specialized types are called integrins) are, as their name suggests, integrated completely into the membrane structure, and their hydrophobic membrane-spanning regions interact with the hydrophobic region of the the phospholipid bilayer .
  • Some complex proteins are composed of up to 12 segments of a single protein, which are extensively folded and embedded in the membrane.
  • This arrangement of regions of the protein tends to orient the protein alongside the phospholipids, with the hydrophobic region of the protein adjacent to the tails of the phospholipids and the hydrophilic region or regions of the protein protruding from the membrane and in contact with the cytosol or extracellular fluid.

• The Relationship Between Genes and Proteins

  • There is increasing evidence from research that profiles the transcriptome of cells (the complete set all RNA transcripts present in a cell) that these may be the largest classes of RNAs produced by eukaryotic cells, far outnumbering the protein-encoding messenger RNAs (mRNAs), but the 20,000 protein-encoding genes typically found in animal cells, and the 30,o00 protein-encoding genes typically found in plant cells, nonetheless have huge impacts on cellular functioning.
  • Protein-encoding genes specify the sequences of amino acids, which are the building blocks of proteins .
  • Both protein-encoding genes and the proteins that are their gene products are absolutely essential to life as we know it.
  • Translation makes protein from mRNA.
  • The polypeptide chain folds up to become a protein.