Search results
Results from the WOW.Com Content Network
Protein before and after folding Results of protein folding. Protein folding is the physical process by which a protein, after synthesis by a ribosome as a linear chain of amino acids, changes from an unstable random coil into a more ordered three-dimensional structure.
Misfolded proteins can form protein aggregates or amyloid fibrils, get degraded, or refold back to its native structure. In molecular biology, protein aggregation is a phenomenon in which intrinsically-disordered or mis-folded proteins aggregate (i.e., accumulate and clump together) either intra- or extracellularly.
An overwhelming load of misfolded proteins or simply the over-expression of proteins (e.g. IgG) [13] requires more of the available BiP/Grp78 to bind to the exposed hydrophobic regions of these proteins, and consequently BiP/Grp78 dissociates from these receptor sites to meet this requirement. Dissociation from the intracellular receptor ...
When proteins are determined to be unfolded or misfolded, they are typically degraded via the unfolded protein response (UPR) or endoplasmic-reticulum-associated protein degradation (ERAD). Substrates that are unfolded, misfolded, or no longer required for cellular function can also be ubiquitin tagged for degradation by ATP dependent proteases ...
Proteasomes are part of a major mechanism by which cells regulate the concentration of particular proteins and degrade misfolded proteins. Proteins are tagged for degradation with a small protein called ubiquitin. The tagging reaction is catalyzed by enzymes called ubiquitin ligases. Once a protein is tagged with a single ubiquitin molecule ...
Endoplasmic-reticulum-associated protein degradation is one of several protein degradation pathways in the ER. Endoplasmic-reticulum-associated protein degradation (ERAD) designates a cellular pathway which targets misfolded proteins of the endoplasmic reticulum for ubiquitination and subsequent degradation by a protein-degrading complex, called the proteasome.
The majority of molecular chaperones do not convey any steric information for protein folding, and instead assist in protein folding by binding to and stabilizing folding intermediates until the polypeptide chain is fully translated. The specific mode of function of chaperones differs based on their target proteins and location.
The cyclic light-dependent reactions occur only when the sole photosystem being used is photosystem I. Photosystem I excites electrons which then cycle from the transport protein, ferredoxin (Fd), to the cytochrome complex, b 6 f, to another transport protein, plastocyanin (Pc), and back to photosystem I. A proton gradient is created across the ...