Protein structural integrity

Cysteine residues form disulfide bonds, which are important to protein structural integrity. Shuffling of these bonds, where two sulfur atoms from two different amino acid molecules link up, often changes the 3D structure, causing a loss of activity. 

THE CHLORIDE DEMAND IN OXYGEN EVOLUTION IS DETERMINED BY THE PROTEIN STRUCTURAL INTEGRITY WITHIN PHOTOSYSTEM II... 

The Chloride Demand in Oxygen Evolution is Determined by the Protein Structural Integrity Within Photosystem II 749... 

Narayanasami R, Horowitz PM, Masters BS (1995) Flavin-binding and protein structural integrity studies on NADPH-cytochrome P450 reductase are consistent with the presence of distinct domain. Arch Biochem Biophys 316 267-274... 

Extrusion as well as reconstitution reactions appear to be an excellent tool in the identification of the active sites in numerous iron-sulfur proteins and enzymes in which the sites cannot be directly investigated. However there are some requirements for the use of this technique, e.g. protein solubility and stability under denaturing conditions, and distinctive spectral or other characteristics permitting the differentiation of the extrusion products from the halo-protein. Structural integrity of the core during and after extrusion also appears as an important condition. Indeed, in some cases it has been observed that an equilibrium dimer-tetramer can occur. 

It is important to notice that the united-atom simplification cannot be applied to functional hydrogens which are involved in the formation of a hydrogen hond or a salt bridge. This would destroy interactions important for the structural integrity of the protein. Removing the hydrogen at the u-carbon of the peptide backbone is also dangerous, because it prevents racemization of the amino acid. 

This difference m reactivity especially toward hydrolysis has an important result We 11 see m Chapter 27 that the structure and function of proteins are critical to life Itself The bonds mainly responsible for the structure of proteins are amide bonds which are about 100 times more stable to hydrolysis than ester bonds These amide bonds are stable enough to maintain the structural integrity of proteins m an aqueous environment but susceptible enough to hydrolysis to be broken when the occasion demands... 

FIGURE 9.31 The known proteoglycans include a variety of structures. The carbohydrate groups of proteoglycans are predominantly glycosaminoglycans O-linked to serine residues. Proteoglycans include both soluble proteins and integral transmembrane proteins. 

Dey S., Alpha Helical Peptide Nucleic Acids (Alpha PNAs) - Integration of Protein Structure and Nucleic Acid Function. PhD thesis. Case Western Reserve University, Cleveland, OH, January 2001. 

Myosinbinding protein C Arranged transversely in sarcomere A-bands Binds myosin and titin. Plays a role in maintaining the structural integrity of the sarcomere. 

The structural and functional integrity of organoclay-wrapped Mb and Hb molecules was demonstrated by retention of the secondary protein structure as well as distinctive shifts in the absorption spectra associated with oxygen or carbon monoxide binding to the heme metallocenter. The latter indicated that the wrapped... 

It is important that the method used to detach cells from their growing surface is compatible with end use. For final use as cell control material, it is important to use a methodology that preserves structural integrity and membrane protein localization. Enzymatic-based reagents may affect proteins on the surface of cells. 

This would prevent intimate contact between the adsorbed protein molecules and the PS surface. As a result, the structural integrity of the protein is expected to be less perturbed. 

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