Crosslinking amino acids

Fujimoto, D., Horiuchi, K. and Hirama, M. (1981) Isotrityrosine, a new crosslinking amino-acid isolated from Ascaris cuticle collagen. Biochemical and Biophysical Research Communications 99, 637-643. 

Sakura, S. and Fujimoto, D. (1984) Absorbtion and fluorescence studies of tyrosine derived crosslinking amino acids from collagen. Photochemistry and Photobiology 40, 731-734. 

Figure 1 Design of a crosslinkable amino acid sequence based on the elastin-mimetic repeat Lys-25.

Fujimoto D, Hirama M and Iwashita T (1982) Histidinoalanine, a new crosslinking amino acid, in calcified tissue collagen. Biochem Biophys Res Comm 104, 1102-1106. 

Nakamura F, Yamazaki K and Suyama K (1992) Isolation and structural characterization of a new crosslinking amino acid, cyclopentenosine, from the acid hydrolysate of elastin. Biochem Biophys Res Comm 186, 1533-1538. 

Suyama K, Yamazaki K and Nakamura P (1995) Gyclopentenosine, trifunctional crosslinking amino acid of elastin and collagen, characterization and distribution. Spec Publ - R Soc Chem 151, 425. 

Isolated from bovine ligamentum. Bovine bone matrix collagen. The lysine-derived crosslinking amino acids are not calculated (N.C.). Composition taken from ref. 2. eSee text and Figure 4. 

These studies focused attention on the crosslinked amino acid derivative, lysinoalanine (IAL), and its possible toxicity. Although the treatments used almost certainly caused significant racemization, the possible effect of D-amino acids on the results was not evaluated. 

Friedman, M. (1977). Crosslinking amino acids—stereochemistry and nomenclature. Li "Protein Crosslinking Nutritional and Medical Consequences", (M. Friedman, ed.), Plenum Press, New York, pp. 1-27. 

Friedman, M. (1977). Crosslinking amino acids—stereochemistry and nomenclature. Reference 1, pp. 1-27. 

Table 1.2. Post-translational changes to proteins the modified coded amino acids present in proteins, including crosslinking amino acids (secondary amino acids)... 

The two purposes of separation of amino-acid and peptide mixtures are either at the preparative level, to isolate one or more individual components from the mixture for further study or at the analytical level, to identify and to determine the relative amounts of some or all of the components. Most of the routine studies, conducted daily to determine the amino-acid content of clinical and botanical samples in hundreds of laboratories around the world, are at the analytical level. However, many of the research studies are at the preparative level an example of this is the identification of crosslinking amino acids from proteins, through their isolation from protein hydrolysates, from physiological specimens for medical investigations, or purely to gain new knowledge. 

Additional crosslinked amino acids can, in theory, arise from interactions of the NH group of histidine, the aliphatic OH groups of serine and threonine, and the phenolic group of tyrosine with the double bond of dehydroalanine and methyl-dehydroalanine (Figure 7). 

Figure 7. Postulated structures of crosslinked amino acids derived from interaction of protein functional groups (NH, NH2, OH, SH) with the double bond of dehydroalanine and methyl dehydroalanine side chains. Asymmetric centers are designated by asterisks.

Keller, S., Ghosh, A. K., Turino, G. M., and Mandl, I. (1984). Separation of the crosslinking amino acids of elastin on thin-layer plates. J. Chromatogr. 305 461-464. 

High yield for 8 carbon linker using homochiral crosslinking amino acids... 

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