Asparagine amide

DV Kashelikar, C Ressler. An oxygen-18 study of the dehydration of asparagine amide by N,N -dicyclohexylcarbodiimide and p-toluenesulfonyl chloride. J Am Chem Soc 86, 2467, 1964. 

The carbohydrate portion of glycoproteins is formed from UDP-iV-acetylglucosamine and CMP-A-acetylneuraminic acid, and is attached to the protein by A-glycosidic bonds to asparagine amide groups. 

The phenolic hydroxyl group of tyrosine, the imidazole moiety of histidine, and the amide groups of asparagine and glutamine are often not protected in peptide synthesis, since it is usually unnecessary. The protection of the hydroxyl group in serine and threonine (O-acetylation or O-benzylation) is not needed in the azide condensation procedure but may become important when other activation methods are used. 

As a p hydroxy derivative of phenylalanine tyrosine has properties similar to those of phenylalanine plus the ability to engage m hydrogen bonding via its —OH group Asparagine and glutamine are not amines they are amides The side chains of both O... 

The only sequence-specific hydrogen bonds between TBP side chains and the bases in the minor groove occur at the very center of the TATA box (Figure 9.7). The amide groups of two asparagine side chains donate four hydrogen bonds, two each to adjacent bases on the same DNA strand (Asn 69... 

Asparagine and glutamine are not fflnines they are amides. The side chains of both O... 

The major classes of glycoproteins are O-linked (involving an OH of serine or threonine), N-linked (involving the N of the amide group of asparagine), and glycosylphosphatidylinositol (GPi)-linked. 

The complex oligosaccharides comprising the Y and T antennae of three glycoproteins have been studied by c.d. spectroscopy. Five antennae were studied in all, because two of the proteins have two closely related forms. The c.d. for the three fundamental oligosaccharides are given in Fig. 36. These are asparagine-linked glycopeptides, and the intense, conservative c.d. band that results from the interaction between the two amides has already been discussed in Section III,2. Fig. 36 shows that the c.d. spectra... 

COOH (asparagine, glutamine) -nh2 Covalent after carboxy activation -> amide... 

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