Interactions amino acids

Our potential is a sum of smooth surface potentials that model amino acid-solvent interactions and of smooth pair potentials that model amino acid-amino acid interactions. As in [24], we take as essential only the Ca atoms. 

Sapse, A.-M., and D. C. Jain. 1986. Guanine and Adenine-Amino Acids Interactions An Ah Initio Study. Int. J. Quantum Chem. 29, 23-29. 

Sayano, K. Kono, H. Gromiha, M. M. Sarai, A., Multicanonical Monte Carlo calculation of the free-energy map of the base-amino acid interaction, J. Comput. Chem. 2000, 21, 954-962... 

This method is very useful for separating amino acids found in food samples. The most effective matrix for separation is an absorbent cellulose-based filter paper. A very effective mobile phase is 70% isopropyl alcohol in water. Although the 20 amino acids are chemically very similar, they may be successfully separated by this method. Amino acids interact with the stationary phase to different extents, thus moving at different speeds. Chemical differences among amino acids that determine migration speed include molecular weight, charge, and polarity. 

Lathrop, R. FI. (1994). The protein threading problem with sequence amino acid interaction preferences is NP-complete. Protein Eng. 7, 1059—1068. 

L-Canaline shares with canavanine an appreciable potential for eliciting adverse biological effects. Evaluations with].. minor of some 55 naturally occurring and synthetic amino acids indicated that canavanine and canaline were amongst the most toxic canaline exhibited slightly greater growth-inhibition than canavanine ( ). These toxic non-protein amino acids interact to curtail additively the proliferation of this aquatic plant (24). 

Yeh, L. S. L., Ingraham, L. L. A study of lumiflavin-amino acid interactions and their relation to the stability of the semiquinone form of flavin. In Flavins and flavoproteins (Singer, T. P. ed.) pp. 765-774, Amsterdam, Elsevier 1976... 

The appearance in the spectrum of the membrane of peaks assigned to amino acids of the protein, only after the membrane has been placed in urea or trifluoroacetic acid, shows that the segmental motion of these amino acid groups is inhibited by high local viscosity when the membrane is present in normal D20. The spectroscopic evidence suggests that the polymethylene chains of the lipid and some of the amino acids of the protein may be mutually interlocked. However, both lipid-lipid and amino acid-amino acid interactions could also be occurring. 

Several U.S. researchers speculate that the authors of the French report mistakenly drew their conclusion from published studies analyzing naturally occurring creatine found in protein-rich animal products such as beef and pork. When these creatine-containing foods are heated and cooked, the creatine and amino acids interact to form compounds known as heterocyclic amines (HCAs), which have been shown to cause cancer in animal studies. The level of HCAs can vary with cooking method and other factors. Creatine monohydrate does not contain HCAs, and as of early 2002, no published or reported clinical research existed to demonstrate that creatine monohydrate taken in supplement form causes cancer. 

The flavor industry has introduced, over the years, methods of developing meat flavors by processing appropriate precursors under carefully controlled reaction conditions. As a result, meat flavors having a remarkably genuine meat character in the beef, chicken and pork tonalities are available for the food industry. It has repeatedly been stated that the Maillard reaction is particularly important for the formation of meat flavors. However, of the 600 volatile compounds isolated from natural beef aroma, only 12% of them find their origin in sugar/amino acid interactions and of these 70% are pyrazine derivatives. 

Curran, P.F., Schultz, S.G., Chez, R.A., Fuisz, R.E. (1967). Kinetic relations of sodium amino acid interactions at the mucosal border of the intestine. J. Gen. Physiol. 50,1261-1286. 

Figure 4.3 ADPGlc PPase tetramer and interactions between the monomers in the tetramer. The figure shows amino acid interactions between the monomers and the ADPGlc PPase catalytic (small) subunit tetramer. (The full color version of this figure can be found atwww.Elsevier.books.com/)...

Lipid oxidation products react with proteins and other amino compounds to form brown substances, similar to melanoidins. The formation of such brown substances was reviewed already at the first Maillard Symposium.150 The pigments formed are partly soluble in chloroform-methanol and partly insoluble, whereas true melanoidins are largely water-soluble. As most brown pigments of fish muscle are soluble in benzene-methanol and only to a lesser extent in water, the implication is that here oxidised lipid-protein interactions are more important than Maillard browning due to ribose-amino acid interactions. 

Major amino acids interacting Aspartic Glycine Serine Leucine Phenylalanine Arginine... 

X-ray crystal structure studies of influenza A/N2, A/N9, and B sialidases bound with a-Neu5Ac [66] show that the active site contains 18 invariant amino acid residues that either interact with the bound a-Neu5Ac or support these residues. These residues are conserved in all strains of influenza A and B viruses, suggesting their involvement in the enzymatic activity [65,66], The residues helped define the topology of the active site [66, 67], Of those conserved amino acids interacting with the substrate, many are polar, but there are also a number of nonpolar residues... 

The time required for each amino acid to pass through the column (its retention time) depends on how strongly that amino acid interacts with the ion-exchange resin. The retention time of each amino acid is known from standardization with pure amino acids. The amino acids present in the sample are identified by comparing their retention times with the known values. The area under each peak is nearly proportional to the amount of the amino acid producing that peak, so we can determine the relative amounts of amino acids present. 

Goodfellow JM, Finney JL, Barnes P (1982) Monte Carlo computer simulation of water-amino acid interactions. Proc R Soc Lond B214 213-228... 

The calculation of the energy or the fitting of the test sequence in the fold of the template is no easy matter. The utilization of a full force field with complete atom representation does not properly discriminate between the different folds [31]. This seems to be related to an energy surface that is too fine and the presence of numerous local minima. In its place a potential function based on a statistical analysis of known protein structures has been developed [34], The pair-wise penalty function provides a pseudo-energy based on the number of times the specific interaction has been observed in known protein structures. This function provides amino acid-amino acid interactions as well as a measure for the solvent exposure of each amino acid [34],... 

The size and complexity of extended biomacromolecules makes the understanding of the various energy contributions which contribute to their stabilization difficult, since only calculations using simple empirical potential calculations are tractable. Fortunately, the most importance biomacromolecules, DNA and proteins, consist of characteristic building blocks-the nucleic acid bases and amino acids-interacting through noncovalent interactions. The system can therefore be fragmented into smaller components, each of which can be described by means of ab initio quantum chemical methods. 

One of the most popular methods of single-stage amino acid derivatization at present is their conversion to N,0 S) err-butyldimethylsilyl derivatives [the reagent rert-butyldimethylsilyl trifluoroacetamide (MTBSTFA) or its A-Me analog]. Another way, which was proposed at the beginning of the 1970s is based on amino acid interaction with dimethylformamide di-alkylacetals (CH3)2NCH(OR )2 (R = Me, Et, Pr, iso-Pr, Bu, Am) with formation of A-dimethylaminometh-ylene derivatives of amino acids esters ... 

The amino acid interactions that determine the formation of stable secondary and tertiary structures can only be characterized in a well defined chemical environment. For this reason, the energetic and kinetic aspects of protein folding have been deduced primarily from in-vitro experiments. 

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