Dityrosine linkages

Disulfide bridges (crosslinkages) 65, 80 cleavage of 115-116 cleavage with performic acid 115 locating 119 in proteins 80 reduction of 115, 785 Dithioerythritol 115 Dithionite ion 779 Dithiothreitol 98,115, 822 Dityrosine linkages 81 DMSO reductase 890 DNA... 

Covalent linkage between two amino acid side chains within a single polypeptide chain appears to be a surprisingly coimnon modification that may serve a function in the structure or reactivity of the protein. In addition to the cross-linked o,o -dityrosine dimers vide supra. Section 2.5) and the quinocofactor, LTQ vide supra, Section 3.1.2), a number of other covalent sttuctures have been identified, mainly by X-ray crystallography. These cross-linked amino acid derivatives include cysteinyl-tyrosine (22), histidyl-tyrosine (23), and cysteinyl-histidine (24). 

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