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Phosphoamino acids stability

The hydrolysis conditions of phosphoamino acids with respect of stability and reproducibility of quantitative determination are discussed by Bylund and Huang (1976). Anal Biochem 73 477). [Pg.48]

From these observations it follows that (1) some of the chemical properties of a phosphoamino acid may change considerably on incorporation into a peptide or protein, (2) that the adjacent molecular configuration may be responsible for the stability of the phosphate group, and (3) that the acidity of the medium determines whether migration of a phosphoric acid residue from the —0— to the —— position occurs. As outlined in a previous section in this article A-phosphorylserine and A-phosphorylthreonine, respectively, w-ould represent possible configurations of the A-terminal amino acid of a peptide chain in a native protein. [Pg.9]

A second property in common to all phosphoproteins is the great lability of the phosphate groups in dilute alkali, in contrast to the stability of phosphoamino acids in this medium. [Pg.26]

The stability of protected phosphoamino acid derivatives in 20% piperidine in DMF was examined in detail by Wakamiya et al. [123]. This study revealed that 8-elimination occurs in the diphenyl protected phosphate, but for the Bzl(4-N02), Bzl, and Me groups the cleavage of one protecting group to produce the O-monoprotected phosphono derivatives occurs faster than the jS-elimination. [Pg.443]

The cellular and in vivo use of natural phosphoamino acid-containing peptides has severe limitations because, in addition to the poor chemical stability of the 0-phosphate group, they are subjected to dephosphorylation by phosphatases and are poorly absorbed into cells. These circumstances and the potential therapeutic use of compounds containing enzymatically and chemically stable phosphoamino acid isosteres have motivated the synthesis of phosphoamino mimetics. Figure 20 shows some selected examples of phosphotyrosine (44 [175-177], 45 [176], 46 [178], 47 [179], 48-49 [177], 50 [180], 51 [177], 52 [181], 53 [182], 54 [183], 55-56 [184,185], 57 [186]), phosphoserine (58 [187], 59 [188], 60 [189,190], and phosphothreonine (61 [191]) mimetics. These building blocks have been incorporated into peptides and peptidomimetics by solid-phase synthesis using standard procedures [175,179,182,183,189,192-198]. [Pg.455]


See other pages where Phosphoamino acids stability is mentioned: [Pg.8]    [Pg.107]   
See also in sourсe #XX -- [ Pg.9 , Pg.26 ]




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