Aspartate, asparagine from

Aspartic acid.was first obtained by Plisson, in 1827, from asparagine by boiling it with lead hydroxide, and is usually prepared from this compound by hydrolysis with alkali or acid. 

The type III j8 turn is similar to a type I turn but has the ( ), angles of a 310 helix and the two chains emerging from the turn are not as nearly parallel as they are in type I turns. Beta turns of the less common types Y, IT, and III have a left-handed twist. As can be seen in Fig. 2-24, this permits a better match to the twist of strands in a P sheet. Unless glycine is present, these bends are less stable because of steric hindrance.214 215 Polar side chain groups such as those of aspartate or asparagine often form hydrogen bonds to the central peptide units of P turns.214... 

About 20% of the X-chromosomes in American Blacks contain A+. It has about the same enzymatic activity as B+ but has higher electrophoretic mobility because aspartate replaces asparagine due to a A— > G mutation at nucleotide (nt) 376 (65). The G-6-PD deficiency typical of Blacks is A— this has always one amino acid substitution in addition to the mutation which characterizes A+. The most common second mutation in A— is G— > A at nt 202. However, there may be mutations at nt 680 or nt 968 instead. Thus, at the molecular level, there are three A- variants instead of one. On the other hand, a few separately recorded variants were at first erroneously thought to be distinct from A-. In any case, all African deficiency variants are descendants of A+ (66). 

A sequence consists of letters selected from an alphabet. The complexity of the alphabet is defined as the number of different letters it contains. The complexity is 4 for nucleic acids and 20 for proteins. Sometimes additional characters are used to indicate ambiguities in the identity of a particular base or residue—for example, B for aspartate or asparagine and Z for glutamate or glutamine (in nucleic acids R for A or G, and Y for C, T, or U). 

Some of the amino acids undergo facilitated diffusion through selective transport proteins into the bloodstream, from which they are taken up by the liver and other organs. Others, particularly glutamate, glutamine, aspartate, and asparagine, are metabolized by the gut cells for energy. 

Simple imide link from asparagine or glutamine to aspartic or glutamic acids... 

Although the precision of analysis with our present technology is often 1 to 3 %, the quantitative release of many amino acids and amino acid derivatives from proteins is often difficult and lowers the overall precision. For example, if constant-boiling HCl (about 5.7 N) is used to hydrolyze a protein in vacuo at 110°C for 24 hr (these conditions are those most commonly used), the amounts of aspartic acid, asparagine, serine, threonine, glutamic acid, glutamine, valine, isoleucine, methionine, tyrosine, tryptophan, cysteine and cystine present in the... 

Fig. 3.1-6 CTPases contain a conserved aspartate that hydrogen bonds to the guanine of GTP. An aspartate to asparagine mutation changes the nucleotide specificity from GTP to XTP by altering these hydrogen bonds.

Fig. 39.13. Synthesis and degradation of aspartate and asparagine. Note that the amide nitrogen of asparagine is derived from glutamine. (The amide nitrogen of glutamine comes from see Fig. 39.9.)...

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