Primary amino acids

In studies with a sulfonyl-resistant biotype of redroot pigweed, the first weed in Israel to exhibit ALS resistance, Sibony et al. (2001) found it was cross-resistant to all other classes of ALS herbicides. From nucleotide sequencing, they concluded that a proline to leucine change in Domain A at position 248 is the only difference in the amino acid primary structure of the regions sequenced, indicating that it is responsible for all ALS inhibitor resistance observed. 

Decarboxylation aC—COOH Amino acid - primary amine -1- CO2... 

Compound Number of amino acids Primary sequence Synthesis and auditing ... 

Somatrein, the flrsi recombinant preparation, introduced in 1985. contains the natural 191-amino acid primary sequence plus one ntethionyl residue on the N-lerminal end. Hie sontatnipin products all contain the 191 -amino acid sequence and are identical with the hGH produced by the piiui-luiy gland. The thiee-dimen.sional cry.stal structure shows ihjl the protein is oblate, with most of its nonpolar amino acid side chains projecting toward the interior of the molecule. This rhGH is pharmacologically identical with natural hGH. 

A prerequisite for the catalytic function of an enzyme is its native tertiary structure which is determined by the number and sequence of amino acids (primary structure) forming the molecule. Favoured by hydrogen bonds, parts of the polypeptide chain exist in an a-helical or a (3-sheet structure (secondary structure). Most enzymes are globular proteins, the tertiary structure of which may be fixed by disulfide bonds between cysteine residues. A famous example is lysozyme (Fig. 20), consisting of 129 amino acids. A defined three-dimensional structure is... 

Corynebacterium sp. Ketose—L-a-amino acid (primary amino) 250... 

Allelic polymorphism in a specific gene can produce nearly identical proteins with primary sequences that differ by one or more amino acids. Primary sequence isoforms can be readily separated by CIEF on the basis of their pi if the amino acid substitution changes the surface charge of the protein. Similarly, enzymatic or nonenzymatic posttranslational chemical modification of ionizable protein functional groups can produce chemically distinct isoforms of the same protein with detectably different surface charge and pi. Analysis of hemoglobin by CIEF is an excellent example of how this technique can be applied for the identification and quantification of a family of related proteins that represent a concise subset of the human proteome. Members of this family include many primary... 

Side-by-Side Images of Amino Acids Primary through Quaternary Structure of Proteins How Does DNA Work ... 

Basic Research. One major area of proteomic research is to understand how the amino acid primary sequence specifies the stability and dynamics of protein conformation. This research would provide information on how to design novel functionalities of proteins and on disorders that work by changing a protein s three-dimensional structure, such as amyloidosis and prion diseases. Studying the folding and unfolding of proteins will help scientists understand the three-dimensional structures of proteins. 

Figure 2. Amino acid primary sequence of the YT320 protein.

Grosvenor, P., and Gray, D. O. (1990). 2,4-Dinotrophenylpyridium chloride, a novel and versatile reagent for the detection of amino acids, primary and secondary amines, thiols, thiolactones, and carboxylic acids during planar chromatography. J. Chromatogr. 504 456-463. 

Derived from esters of amino acids. Primary amines only. 

The nitrogenous components of grapes and must that are metabolically available to yeast are present as ammonium salts (NH4 ) and amino acids primary, collectively known as yeast assimilable nitrogen (YAN). Therefore, a complete evaluation of the nutritional status of juice or must requires measurement of both fractions. The total nitrogen content of juice not only contains YAN but peptides and proteins as well. However, the latter two fractions are not thought to play a significant role in the nutritional needs of Saccharomyces during fermentation. 

Similar to amino acids, primary aliphatic amines give a very sensitive color reaction with ninhydrin (see p. 278). In view of its sensitivity, it is advisable to combine the test with paper chromatography (p. 347). For the procedure see p. 278 (amino acids). 

Fluorimetric reagent for amino acids, primary amines, peptides, proteins and proteolytic enzymes. Cryst. (CH2Cl2/Et20). Mp 154-155°. 

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