Amino acid compositional data

Amino acid composition data and stable isotope ratios are being evaluated as sources of information to indicate the presence of non-indigenous organics in bone samples intended for radiocarbon analyses. The study is being conducted in the context of the planned 14C measurement of Pleistocene bone samples by high energy mass spectrometric methods. 

The development of the commercial amino acid analyzer based on the ion-exchange method led to the rapid accumulation of compositional data on the amino acids in citrus. Many investigators have published amino acid compositional data. A summary from a recent review (76) is presented in Table II. These data make it relatively easy to detect adulterations with amino acids, although the equipment and analyses are expensive for routine testing. 

The values for the molecular weight of plant ferredoxins reported by different investigators are not in agreement. Appella and San Pietro 4) reported a molecular weight of 17,000 for spinach ferredoxin, based on an S2o,w of 1.36 and a diffusion coefficient of 6.6 X 10 7 cm2/sec. The partial specific volume was assumed to be 0.71. A calculation by the writer for the minimal molecular weight of spinach ferredoxin from available amino acid composition data Fry and San Pietro (47)) and the assumption of six cysteine residues per mole gave a value of 13,000. Arnon (5)... 

Latter et al have recently published the results of a study in which cells growing in culture were labelled with 20 radioactive amino acids, each in a different experiment, and analyzed by 2D6EL (S4). The resulting autoradiographs were studied with an image analysis system so that amino acid compositional data could be extracted. This information was then compared to the amino acid composition data resident in two large data bases, using computerized search methods. Out of the 122 spots studied in this manner, tentative identifications could be made on 17 of them based on the amino acid composition alone. 

Table 1 Amino acid composition data for two tryptic peptides derived from bovine growth hormone...

FIGURE 5.5 (a) The hydroxy amino acids serine and threonine are slowly destroyed during the course of protein hydrolysis for amino acid composition analysis. Extrapolation of the data back to time zero allows an accurate estimation of the amonnt of these amino acids originally present in the protein sample, (b) Peptide bonds involving hydrophobic amino acid residues snch as valine and isolencine resist hydrolysis by HCl. With time, these amino acids are released and their free concentrations approach a limiting value that can be approximated with reliability. 

This key enzyme of the dissimilatory sulfate reduction was isolated from all Desulfovibrio strains studied until now 135), and from some sulfur oxidizing bacteria and thermophilic Archaea 136, 137). The enzymes isolated from sulfate-reducing bacteria contain two [4Fe-4S] clusters and a flavin group (FAD) as demonstrated by visible, EPR, and Mossbauer spectroscopies. With a total molecular mass ranging from 150 to 220 kDa, APS reductases have a subunit composition of the type 012)32 or 02)3. The subunit molecular mass is approximately 70 and 20 kDa for the a and )3 subunits, respectively. Amino-acid sequence data suggest that both iron-sulfur clusters are located in the (3 subunit... 

Quantitative information may also be gained from the data. If the amino acid composition is accurately known, it may prove possible to integrate portions of the 13C-n.m.r. spectra in order to gain quantitative information about the oligosaccharide structure. This also assumes that no differential nuclear Overhauser effects (n.O.e. s) exist between the various resonances and that none of the resonances in question are attenuated by the use of short recycle-times. 

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. 

Amino acid composition MA, MI, FLAG, and CYL from Dicko et al. (2004b), Acinous and Pyriform from unpublished data, Bombyx mori, Antheraea pemyi, and Galleria mellonella from sequences. 

From amino acid compositions, evaluations o7" the nutritional potentials of cucurbit meals and globulins can be calculated according to FA0/WH0 (54). The A E ratios, which are the amounts of each essential amino acid relative to the total amount of essential amino acids, are shown in Table II. These data indicate that, like most other oilseeds, cucurbit seeds are deficient in lysine and sulfur-containing amino acids. However, sulfur-containing amino acids are considerably high in CitrullI us colocynthis (egusi, ancestral watermelon) seed protein and exceed the suggested level in FA0/WH0 reference protein (55). 

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-... 

On the other hand, the prediction by content approach is applicable regardless of the variety of sorting pathways. It may be applied to partial sequences, which are now massively produced day by day. In addition, this approach allows a simple and unified treatment, which is convenient for objective testing (e.g., cross validation). However, there is no guarantee that the amino acid composition of proteins in each localization site is well conserved. Even when a clear tendency is observed for a known set of proteins, it can be an artifact resulting from the deviation of data because the size of known proteins for each site is often insufficient to perform reliable statistical analyses. It is also evident that this approach cannot handle the differences among isoforms with different localization (see Section III,K,3). 

Not only is the amino acid composition of each saliva distinctive, but available data with respect to different electrolytes suggest that inter-individual variation in composition may also be large in these instances (Table 11). 54,55,56 Differences in mode of collection and in the diets of the subjects tend to lessen the meaning of these data. 

MULTIIDENT (Proteins Identification Using pi, MW, Amino Acid Composition, Sequence Tag and Peptide Mass Fingerprinting Data)... 

TABLE 5.12 Amino acid composition (g/100 g milk dry matter basis) of morama bean milk compared with a commercial soybean milk Source Data adapted from Jackson et al. (2009) and Liu (1997)... 

The evidence for the presence of the proteinaceous material in the biocrystalline layer is based on amino acid analyses368. Systematic studies of the amino acid composition of the biocrystalline layer of egg shells from Galliformes, Gruiformes and Anseriformes and reptiles gave hints to different development within orders of the classes Aves and Reptilia378-380. From the data of the amino acid composition of ratite egg shells, affinities could be derived362. ... 

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