Proteins comparative

The individual role of isoflavones contained in soy protein compared to isoflavones alone has not been systematically studied. In addition, it is possible that some of the minor components of soy also play a biological role. Nevertheless, in terms of bone health, the benefit of soy diets is largely attributed to the isoflavones due to their weak estrogenic activity and potential to alleviate the estrogen loss following the menopause. 

The essential distinction between the approaches used to formulate and evaluate proteins, compared with conventional low molecular weight drugs, lies in the need to maintain several levels of protein structure and the unique chemical and physical properties that these higher-order structures convey. Proteins are condensation polymers of amino acids, joined by peptide bonds. The levels of protein architecture are typically described in terms of the four orders of structure [23,24] depicted in Fig. 2. The primary structure refers to the sequence of amino acids and the location of any disulfide bonds. Secondary structure is derived from the steric relations of amino acid residues that are close to one another. The alpha-helix and beta-pleated sheet are examples of periodic secondary structure. Tertiary... 

Another important characteristic of oxidative stress in thalassemia is LDL oxidative modification. Livrea et al. [388] showed that the concentration of hydroperoxides in LDL of thalassemia patients was equal to 22.60+ 12.84 nmol/mg LDL protein compared to 6.25 +3.04 nmol/mg in control LDL. These authors proposed that the enhanced LDL oxidation in thalassemia was connected with the depletion of vitamin E in LDL. Interestingly, these findings contradict the suggestion about the prooxidant role of vitamin E (a-tocopherol) in LDL oxidation (Chapter 25). It was proposed that LDL oxidation could be the origin of atherogenetic risk in thalassemic patients. 

Plasma binding - both the quantity and types of proteins in plasma differ in these classes of animals. Mammals tend to have large amounts of protein compared with fish (ca. 8 vs 3 g/100 ml) and albumin, the protein which binds most xenobiotics, is negligible in a number of fish species. 

Elevated concentrations of TNF have been found in the joints of RA patients and the stools of Crohn disease patients and correlate with elevated disease activity. In Crohn disease, infliximab reduces infiltration of inflammatory cells and TNF production in inflamed areas of the intestine and reduces the proportion of mononuclear cells from the lamina propria able to express TNF and interferon. In RA, treatment with infliximab reduced infiltration of inflammatory cells into inflamed areas of the joint as well as expression of molecules mediating cellular adhesion and vascular cell adhesion molecule-1, chemoattraction, and tissue degradation. After treatment with infliximab, patients with Crohn disease or RA have decreased levels of serum IL-6 and C-reactive protein compared with baseline. 

Isolation of alkaline phosphatase from Escherichia coli in which 85% of the proline residues were replaced by 3,4-dehydro-proline affected the heat lability and ultraviolet spectrum of the protein but the important criteria of catalytic function such as the and were unaltered (12). Massive replacement of methionine by selenomethionine in the 0-galactosidase of E. coli also failed to influence the catalytic activity. Canavanine facilely replaced arginine in the alkaline phosphatase of this bacterium at least 13 and perhaps 20 to 22 arginyl residues were substituted. This replacement by canavanine caused subunit accumulation since the altered subunits did not dimerize to yield the active enzyme (21). Nevertheless, these workers stated "There was also formed, however, a significant amount of enzymatically active protein in which most arginine residues had been replaced by canavanine." An earlier study in which either 7-azatryptophan or tryptazan replaced tryptophan resulted in active protein comparable to the native enzyme (14). 

Traditional protein NMR spectroscopy of smaller proteins relies of 15N-filtered experiments, due to the relatively low expense of introducing 15N labels into proteins (compared to 13C) and the concomitant ability to use heteronuclear filtering to improve resolution in the H NMR dimension. Jelinek et al. were the first to demonstrate the ability to transfer this approach to peptides on TantaGel.80 They also showed the ability to detect pronounced peptide structure through the appearance of strong NOE correlations in 3H NOESY HRMAS spectra as shown in Fig. 8. This had important implications for the search of biological activity in peptides attached to supports, as the structure on the support may be different or more pronounced than in solution, if present at all in solution in peptides of this small size. 

Another important characteristic of oxidative stress in thalassemia is LDL oxidative modification. Livrea et al. [388] showed that the concentration of hydroperoxides in LDL of thalassemia patients was equal to 22.60+ 12.84 nmol/mg LDL protein compared to... 

FIGURE 3.9 Western blotting analysis of uncoupling protein 1 (UCP1) in epididymal WAT and relative expression level of UCP1 protein compared to p-actin (Okada etal., 2011). Columns with different superscript letters are significantly different (p<0.05). 

The correlation times of the a carbons in the native protein compared to those of the denaturated biomolecule are much larger, indicating an increased segmental motion in the backbone of denatured ribonuclease. 

Spectrin is a much more elongated protein compared to a-actinin due to the additional number of repeats. The additional repeats are more closely related to one another than repeats common to both a-actinin and spectrin. The spectrin repeat sequences are the most divergent in dystrophin and its homologue utrophin (Winder et al, 1995a), most likely reflecting an earlier divergent event when compared to spectrin (Pascual et al, 1997). 

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