Function amino acid composition

The data presented in Table 3, which includes the amino acid composition of baker s yeast and Candida krusei cytochrome c for comparison, show that Ustilago and Neurospora cytochrome c contain the same number of total residues. In seven instances, the number of residues of a particular amino acid/mole are identical. Thus, even in the absence of a sequence for the Ustilago cytochrome it can be concluded that this protein, unlike the siderochromes, has suffered little alteration in the progression from the Ascomycetes to the Basidiomycetes. This can be ascribed to the varying function of the two types of molecules. Cytochrome c must fit into a relatively specific slot bounded by a reductase and an oxidase and it has hence evolved much more slowly than the more freely acting transport agents where the specificity constraints are less demanding. 

After device construction, structural and functional analysis are critical. One might argue that only the second issue matters, but structural data often give insights into why devices perform suboptimally, and provide important clues about how to improve device function. We routinely use protein analytics (matrix-assisted laser desorption-ionization mass spectroscopy, amino acid composition analysis, gel electrophoresis, Western blotting, circular dichroism, vari-... 

The isolation of an SCP protein from rat liver homogenates has also been reported (S2). This protein has been found to be heat-labile, to be detectable only in the liver, and to have a molecular weight of approximately 50,000 daltons by gel filtration (S2) and 28,000 daltons by sedimentation equilibrium (S3). Although the functional properties of the heat-labile SCP (SI) are similar to the heat-stable SCP (R2, R3), these proteins appear to be different. According to Scallen et al. (S3), their SCP preparation resembles chemically serum LDL this based on the similarity in amino acid composition between these two proteins. In the... 

P-Casein, synthesis, 151,153/ Caseinomacropeptide, laige-scale preparation and application, 211-219 amino acid composition, 219t biological functions, 211 inhibition of cholera toxin-receptor binding, 211-214 isolation procedure, 215,217/218 molecular weights, 215,216/ potential applications, 219 preparation, 215-219 recovery, 218/,219r... 

Iwasaki, N., Noji, S., and Shidara, S. (1975). Achromobacter cycloclastes nitrite reductase. The function of copper, amino acid composition, and ESR spectra. J. Biochem. (Tokyo) 78, 355-361. 

Discarded fish bones and cutoffs may contain considerable amounts of muscle proteins. These muscle proteins are nutritionally valuable and easily digestible with well-balanced amino acid composition (Venugopal et al., 1996). Therefore, fish proteins derived from seafood processing by-products can be hydrolyzed enzymatically to recover protein. Protein hydrolysates from several marine species have been analyzed for their nutritional and functional properties, and researches have mainly explored the possibility of obtaining biologically active peptides (Benkajul and Morrissey, 1997). Moreover, skipjack tuna muscle (Kohama et al., 1988), sardine muscle (Bougatef et al., 2008), and shark meat (Wu et al., 2008) have been used to separate potential peptides. 

In the process of viral assembly, HIV PR specifically cleaves nine cleavage sites on GAG and GAG-POL polypeptides [21]. Examination of the amino acid composition of the recognized substrate sites (Table 1) indicates their hydrophobic character and significant sequence variability. The loose specificity of HIV PR most likely reflects its functions in a world of reduced complexity within the confines of the budding virion. The length of the viral protein precursors (approximately 1500 amino acids) reduces the number of potential sequences the protease must discriminate from in selecting its nine cleavage sites. Therefore,... 

Differences in protein function result from differences in amino acid composition and sequence. Some variations in sequence are possible for a particular protein, with little or no effect on function. 

Found in the chromatin of all eukaryotic cells, histones have molecular weights between 11,000 and 21,000 and are very rich in the basic amino acids arginine and lysine (together these make up about one-fourth of the amino acid residues). All eukaryotic cells have five major classes of histones, differing in molecular weight and amino acid composition (Table 24-3). The H3 histones are nearly identical in amino acid sequence in all eukaryotes, as are the H4 histones, suggesting strict conservation of their functions. For example, only 2 of 102 amino acid residues differ between the H4 histone molecules of peas and cows, and only 8 differ between the H4 histones of humans and yeast. Histones HI, H2A, and H2B show less sequence similarity among eukaryotic species. 

Avery s studies shed light on the function of DNA. Chargaff s touched on structure in that knowing the distribution of A, T, G, and C in DNA is analogous to knowing the amino acid composition of a protein, but not its sequence or three-dimensional shape. 

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