Peptide glycine

The synthesis of DNA analogues with a backbone of poly(/V-(2-amino-ethyl)glycine) (peptide nucleic acids = PNA) instead of phosphate-ribose, which were introduced into affinity labeling by Egholm et al. (28), opened up several new applications for affinity separations (23,28-42). Since this backbone is by far less polar, the behavior of the monomer as well as that of DNA/PNA hybrids is largely different, allowing the complete separation of affinity complexes. In addition, it seems that the stability of duplexes is... 

Methods are presented for calculating mean-square dipole moments, , of polypeptide chains, averaged over all configurations of the chain skeleton. They are applicable to chains of any number (x+ U of residues, the residues being In any specified sequence. Dipole moments of glycine peptides are calculated and compared with experimental determinations. The effects of stereosequence on the dipole moment are well reproduced by the calculations. Ip is taken to be 380 pm. 

Table 10 Ionization Constants of Some Coordinated Glycine Peptides, Showing Metal-ion-promoted Peptide Deprotonations ...

Peptide bond formation using non-labile cobalt(III) complexes has now been developed to a useful synthetic level (Section 61.4.2.2.4), but few attempts have been made to use other metal centres. The formation of glycine peptide esters in the presence of copper(II) has been noted.133 Treatment of glycine esters with copper(II) (other metal ions can also be used) in a non-aqueous solvent at room temperature gave di-, tri- and tetra-glycine peptide esters. After carbobenzyloxyla-tion, the peptide esters were separated by column chromatography, and no evidence was obtained... 

Formally, however, the amino acids contained either in peptides or proteins are named in a fashion related to that used for alkanes. The -ine suffix is replaced by -yl to give, for GAG, glycyl-alanyl-glycine. Peptide and protein sequences are always written and named from the N-terminus to the C-terminus. The C-terminal amino acid retains its full name. 

Synthesis of peptides from amino acids in the solid state or in aqueous solution has been reported with the aid of ATP, Mg2 and free imidazole 34 36). a 4.5 % yield of glycine peptides has been reported in the solid state, 0.6 % yield in aqueous solution 36). Gly-N-pA is formed in a yield of 72.5 % from glycine and chemically synthesized ImpA in aqueous solution, pH 8.0, at room temperature 37). At initial of pH 6.0 glycyl 5 -adenylate (gly-O-pA) and 2 (3 )-0-glycyl adenosine 5 -phosphate (pA-g W are formed 37). 

Complexes with Glycine and Poly(glycine) Peptides... 

Numerous ESR studies of the photodamage effect on biologically important molecules have been reported in recent years. Brustad (377) studied the UV-irradiation of the enzyme trypsin and found a linear correlation of the loss of enzyme activity with concentrations of the photoproduced radical. Leterrier and Douzou (378) have applied ESR techniques to study the mechanism of the photoreduction of flabin mononucleotide. A number of investigations deal with photodamage of aliphatic amino acids, glycine peptides, dipeptides, and alanine peptides (379-383). John et al. 

Table 2.8. N-ALKYL GLYCINE PEPTIDE TFMK INHIBITORS OF HLE ...

Figure 20.5. Transmission electron microscopic (TEM) images of hpid-Uke glycine peptide enclosures. Glycine tail and aspartic acid head peptides formed tube and vesicle structures. Note the growth of the tube opening (A, B, C) and the presumed vesicle division (D). If these dynamic enclosures can encapsulate other biomolecules, this may be one step closer for prebiotic molecular evolution.

Since there were two types of alanine-glycine peptide fragments, one with alanine as the N-terminal amino acid and the other with alanine as the C-terminal amino acid, alanine must be bonded to two glycine portions in the... 

The specificity of assembly of the glycine-peptide is high and appears to derive partly from the enzymes involved, both in activation and polymerisation, and partly from the tRNA itself. 

Ratios of shifts (%) and relative distances for the Pr(III) complexes of the glycine peptides... 

The nucleic acid backbone can be replaced with an N-(2-aminoethyl) glycine peptide backbone to form what has been termed peptide nucleic acids (PNAs). With this replacement, PNAs lack the negative charge from the phosphodiester backbone of regular nucleic acid analog and hence bind more effectively with complementary sequences because of the lack of electrostatic repulsions. As a result, PNAs have been used in biosensors to increase sensitivity and DNA mismatch discrimination. 

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