Alanyl alanine

FIGURE 1.30 Micro-HPLC separation of all 4 stereoisomers of the dipeptide alanyl-alanine as FMOC derivatives (a) and DNP-derivatives (b), respectively, on a 0-9-(tert-butylcarbamoyl)quinine-based CSP. Experimental conditions Column dimension, 150 X 0.5 mm ID mobile phase (a) acetonitrile-methanol (80 20 v/v) containing 400 mM acetic acid and 4 mM triethylamine, and (b) methanol-0.5 M ammonium acetate buffer (80 20 v/v) (pHa 6.0) flow rate, 10 ixLmin temperature, 25 C injection volume, 250 nL detection, UV at 250 nm. (Reproduced fromC. Czerwenka et al., J. Pharm. Biomed. Anal., 30 1789 (2003). With permission.)... 

Figure 22 Intrasheet distances between BC and 170 in the parallel (upper) and anti-parallel (lower) sheets for L-alanyl-alanyl-alanine. Reproduced with permission from Ref. 100.

Fig. 4. Orientation of the shielding tensor elements in the molecular frame on alanyl-alanine, cTn lies essentially in the plane of the peptide linkage as do the N-H, N-Ca,...

CH(CHj). COOH from hippuryl-alanine azide and a-alanine. Hippuryl-alanyl-alanyl-alanine, C H,. CO. NH. CH,. CO — NH. CH(CHJ. CO — NH. CH. (CHj). CO — NH. CH(CHj). COOH from hippuryl-alanyl-alanine azide and a-alanine. 

In the same way alanyl-alanine and alanyl-alanine ester, which yielded caibethoxyl-alanyl-alanine ester when treated with ethylchloro-carbonate, can be obtained from alanine anhydride, and leucyl-leucine from leucine anhydride or leucinimide, which was first obtained in 1849 regarded as occurring in the protein molecule, by... 

Leucyl-alanyl-alanine b f < "° " °= P "y =Woride + alanyl-alanine). Dialanyl-alanine (a-bromopropionylbromide + alanyl-alanine). 

Chemical Shift and its Anisotropy Spin 1/2 Nuclei. - Calculations of NMR chemical shifts in crystalline phases of some representative amino acids such as glycine, alanine, and alanyl-alanine have been reported. The effect of environment on the chemical shifts was explored in selected glycine geometries ranging from the crystalline phase to completely isolated molecules. In the crystalline and dilute molecular limits, the calculated distinct NMR chemical shifts have been attributed to intermolecular hydrogen bonds and dipole electric field effects, respectively. 

In 1972 the team of Professor Zaehner at Tubingen described a Streptomyces strain producing a novel compound with antibiotic properties. The antibiotic tripeptide produced by Streptomyces viridochromogenes consists of two alanine residues and a novel amino acid that was named phosphinothricin [14] (Fig. 6.3.2). Owing to its structural analogy to glutamate Bayer et al. [14] tested and proved the hypothesis that phosphinothricin acts as an inhibitor of bacterial GS enzyme, whereas the tripeptide phosphinothricyl-alanyl.alanine did not inhibit the isolated GS enzyme. Nevertheless the tripeptide was 1.000-10.000-fold more active in its growth inhibitory effect on different bacteria. The discrepancy is explained by the observation that free phosphinothricin cannot be taken up efficiently by bacteria, whereas the tripeptide is taken up into the bacteria by peptide carriers and, subsequently, the tripeptide is cleaved. 

Tipper and Strominger (1965), by comparing molecular models of penicillin and D-alanyl-D-alanine claimed that the former could effectively function as a metabolite analogue of the latter. Thus the N to N" distances in these molecules, shown as projections of molecular models in (13.7) and (13.8), are identical, namely 3.3 A. Also the N" to C distances are similar in both models, namely 2.5 A. From N to C is 5.4 A in the penicillins and 5.7 A in alanyl-alanine, distances which are not identical but still quite similar. The D-con-figuration of the penicillin is maintained by the sulfur atom in conjunction with the carbon atom that is common to both rings. [Epimerization at the 6-position, see (13.4), causes loss of all antibacterial activity.] The most reactive bond in the penicillin molecule (the j8-lactam bond) corresponds in position to the peptide bond joining the two D-alanine residues. However, there are discrepancies the... 

Hy azid dea niedrigeisolimeizendeii Beti> zoyl-alanyl-alanins 9, 250. 

Cliloracetyl-alanyl-alanin 4II826 441blor-5.5-dinietiKtxy-1.3.dimethyl-hydia uracil 24II267. 

Citronensaura-bris-methylamid 4, 79. DialanylaJanin, Alanyl-alanyl-alanin 4, 401, It 812. 

HOherschmelzendes inakt. Benzoybalanyb alanin 9, 249, IT 180. Niediigerschmelzendea inakt. Benzoyl alanyl-alanin 9, 249,1112. ra Benzainino-iBobutyryl] g cin 9, 251. I enace bd-glutamin 9 1176, II 302. y.C Dioximmo-C pbaiyl-dnanthBiure 10,821. 

CnH N40, BenzaIdehyd.[. hiiqiniylamkK>-Duty l.hydrazon] 9, 242. Benzylidenhydrazid dra Benzoyl-alanyl-alanins 9, 250. 

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