Amino acids bonding

Proteias, amino acids bonded through peptide linkages to form macromolecular biopolymers, used as chiral stationary phases for hplc iaclude bovine and human semm albumin, a -acid glycoproteia, ovomucoid, avidin, and ceUobiohydrolase. The bovine semm albumin column is marketed under the name Resolvosil and can be obtained from Phenomenex. The human semm albumin column can be obtained from Alltech Associates, Advanced Separation Technologies, Inc., and J. T. Baker. The a -acid glycoproteia and ceUobiohydrolase can be obtained from Advanced Separation Technologies, Inc. or J. T. Baker, Inc. 

A review11 with 123 references is given on amino acid bonding preferences in complexes of platinum and palladium. The preferences for a particular donor atom for Pd11 depends primarily on relative thermodynamic stabilities of the complexes formed. Sizes of potential chelate rings often play a crucial role in determining donor atom preferences. 

Specificity. The generally claimed specific action of enzymes is not as sharply defined as is often expected. Proteases are broad in the range of amino acid bonds they hydrolyze and exhibit only a degree of specificity. Careful investigation of the range of bonds attacked, and testing for comparable action on the actual protein target, will enable an enzyme to be chosen that has suitable performance. Some proteases are extremely narrow in their action, for example the various cheese rennets. 

Primary Structure the sequence of amino acids bonded to each other in a peptide chain... 

Both the size of the preceding amino acid in the dipeptide X-Pro, and that of groups in the COOR residue are able to influence (730MR547 79MI6) their conformer ratio. The conformational characteristic found for the dipeptide Gly-Pro, with the glycine amino acid bonded to a bulky residue, are close to those of poly (Gly-Pro), suggesting (77MI7) that the conformational behavior of one polymer is related to local properties of dipeptide units. 

Among the microbial surfactant producers, Bacillus subtilis strains generate a lipopeptide called surfactin, one of the most effective biosurfactants known. This biomolecule is usually a cyclic compound consisting of seven amino acids bonded to a lipid moiety. Surfactin is effective in lowering the surface tension of water to <30 dyn/cm (17), which is comparable with the values obtained by conventional synthetic surfactants. Additionally, surfactin preparations have other interesting characteristics, including antibiotic and antiviral properties (18). In fact, surfactin is one of the few biosurfactants that has found commercial use (19). 

While studies on the crystal structures of RE(III)-amino acid complexes can give us clear pictures on the ways in which RE(III) ions and the amino acids bond to each other, their solution chemistry, which deals with the reactions in solution, the chemical species formed, their stability, as well as their distribution over certain pH ranges, can help us understand better the in vivo behaviors of RE(III) ions and their complexes with amino acids. Work on the solution chemistry of RE-amino acid complexes has been carried out since the early 1960s [9]. It has been found that the amino acids studied behave very similarly to one another, just as we have learned from their structural chemistry. Mononuclear species with 1 1 and 1 2 (RE L) stoichiometry have been reported for all of the amino acids. In some studies, the presence of mononuclear species with stoichiometry 1 3, dinuclear species with stoichiometry 2 4 and 2 6, in addition to the hydrolyzed species, such as [RE(OH)L]+, [RE(OH)] +, and RE(OH)3(s), have been confirmed [126, 135, 136]. 

Proteins are constructed from amino acids which are assembled by the formation of peptide bonds. The amino group of one amino acid bonds with the carboxyl group of another, eliminating one water molecule (HOH). The bond between the two amino acids consists of a nitrogen with one hydrogen bonded to a carbon with a double-bonded oxygen H-N-C=0. 

The amino-acid sequence of the polypeptide chain is said to be the primary structure of a protein. Thus, the primary structure of a protein is simply the order in which the amino acids bonded together. 

Amino acids bonded to silica and loaded with Cu ions can interact in a steroselective manner with amino acids in aqueous solution. The copper ion forms a complex with both the bound and the sample amino acids, as shown in Figure 22.1. Ligand-exchange phases are suited for the separation of amino acids as well as of some )3-amino alcohols and similar molecules because these compounds bear two polar functional groups in adequate spacing. This approach has found limited interest because the column efficiencies are rather low, the detectability of the nonderivatized sample compounds can be a problem and the mobile phase needs to contain copper. 

The carbonyl carbon atom of one amino acid bonds to the amine nitrogen of... 

The polymerization reactions that form proteins are condensation reactions, similar to those that are used to make some of the plastics you studied in Chapter 18. When two amino acids bond together, a hydrogen (— H) from the amino group of one amino acid combines with the hydroxyl (— OH) part of the carboxyl group of the other amino acid to... 

The carbonyl carbon atom of one amino acid bonds to the amine nitrogen of another to form an amide group. This bond is called a peptide bond ... 

Amino acids are the subunits from which proteins are made. A protein is a long polymer, or chain, of many amino acids bonded to one another. 

Amino acids are the building blocks of the body s worker molecules called proteins. When two amino acids bond together, they do so through the formation of a peptide linkage, and a dipeptide is formed. Consider the following tripeptide formed when three alanine amino acids bond together ... 

Amino acids are activated through a reaction with ATP yielding an amino acid bonded to AMP. The AMP-bound amino acid is then reacted with a tRNA to yield an amino acyl tRNA. 

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