Aspartic Acids and Arginines

Aspartic acid and arginines are important substrates for the biosynthesis of purine bases. They are also glycosylation sites in proteins. These reasons have been at the origin of the synthesis of their mono and difluoro analogues. 

Monofluoroaspartic acids and monofluoroasparagines have been prepared as racemates via different pathways. For example, dehydrofluorination of difluor- 

The cytotoxicity of fluoroaspartic acids and of fluoroasparagines, their inhibition of the biosynthesis of purines and of the glycosylation of proteins, as well as the inhibition 

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It is noteworthy that there is another limiting factor in the choice of amino acid types at the junction sites which affect the enzymatic process of the intein. For example, in the case of SceVMA (also called PI-Seel) from the IMPACT system, proline, cysteine, asparagine, aspartic acid, and arginine cannot be at the C-terminus of the N-terminal target protein just before the intein sequence. The presence of these residues at this position would either slow down the N-S acyl shift dramatically or lead to immediate hydrolysis of the product from the N-S acyl shift [66]. The compatibility of amino acid types at the proximal sites depends on the specific inteins and needs to be carefully considered during the design of the required expression vectors. The specific amino acid requirements at a particular splicing site depends on the specific intein used and is thus a crucial point in this approach. 

Calculate the isoelectric point for histidine, aspartic acid, and arginine. Calculate the fractional charge for... 

Some cyanobacteria possess cyanophycin, which is a copolymer of aspartic acid and arginine (Lawry and Simon, 1982). This copolymer is accumulated in the granules, and its localization in complexes with PolyP is not improbable. 

Simon, R.D. (1971) Cyanophycin granules from the blue-green alga Anahaena cylindrica a reserve material consisting of copolymers of aspartic acid and arginine. Proc. Natl. Acad. 

Simon, R.D., and Weathers, P. (1976) Determination of the structure of the novel polypeptide containing aspartic acid and arginine which is found in cyanobacteria. Eiochim. Biophys. Acta, 420, 165-176. 

Arginine-aspartic acid and arginine-glutamic acid pairs, as well as the corresponding dipeptides, have been co-crystallized in a systematic manner. These crystal structures (Fig. 9.2.3) allow detailed insight into side-chain interactions, odd-even chain link numbers, and chirality. 

Table 25.4 shows a salt bridge between aspartic acid and arginine. Sketch the analogous electrostatic attraction between lysine and an annino acid other than aspartic acid from Table 25.1. 

Can we utilize this pH-dependent ionization of amino acids for their separation A small example will answer the question. We are given a mixture of three amino acids, alanine, aspartic acid, and arginine. It is required that we separate these three amino acids from each other and obtain them in a more or less pure state. From Table 1.8 we can find out that the pi of alanine. 

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