Photochemical Addition of Amino Acids and Peptides to Homopolyribonucleotides of the Major Dna Bases

Abstract

The photochemical quantum yields for addition of glycine and the L-amino acids commonly occurring in proteins (excluding proline) to polyadenylic acid, polycytidylic acid, polyguanylic acid and polyribothymidylic acid have been determined in deoxygenated phosphate buffer at A 254 nm and pH 7, using a fluorescamine assay technique. Polyadenylic acid was reactive with eleven of the twenty amino acids tested, with phenylalanine, tyrosine, glutamine, lysine and asparagine having the highest quantum yields. Polyguanylic acid reacted with sixteen amino acids; phenylalanine, arginine, cysteine, tyrosine, and lysine displayed the largest quantum yields. Polycytidylic acid showed reactivity with fifteen amino acids with lysine, phenylalanine, cysteine, tyrosine and arginine having the greatest quantum yields. Polyribothymidylic acid, reactive with fifteen of nineteen amino acids surveyed, showed the highest quantum yields for cysteine, phenylalanine, tyrosine, lysine and asparagine. None of the polynucleotides were reactive with aspartic acid or glutamic acid.The quantum yields for photoaddition of eighteen dipeptides of the form glycyl X (X being one of the amino acids commonly occurring in proteins, including proline), and of L-alanyl-L-tryptophan, L-seryl-L-seryl-L-serine, L-threonyl-L-threonyl-L-threonine, L-cystine-bis-glycine. and N"-acetyllysine to polyadenylic acid, polycytidylic acid and polyguanylic acid were measured. All of these were found to add photochemically to each of these polymers. Polyribothymidylic acid, tested with eleven of these peptides and with N"-acetyllysine, was found to be reactive with all.

Identification of RNA-associated peptides, iRAP, defines precise sites of protein-RNA interaction

“…Most amino acids can form photo-adducts with oligo-DNA or RNA sequences when single amino acids are added to the reaction, with Cys, Lys, Phe, Trp, Tyr, His, Glu and Asp being the most reactive amino acids towards DNA (Shetlar, 1980, Shetlar, Christensen et al, 1984, Shetlar, Home et al, 1984. Based on previous analyses (Bley et al, 2011, Connor et al, 1998, Doneanu et al, 2004, Maly et al, 1980, Williams & Konigsberg, 1991, Zwieb & Brimacombe, 1979, aromatic amino acids would also be expected to be among the most reactive with intact proteins, and this was found in our analyses.…”

A novel combined RNA-protein interaction analysis distinguishes HIV-1 Gag protein binding sites from structural change in the viral RNA leader

“…UV irradiation at 254 nm induces cross-links between RNA and protein as nucleobase excitation at this wavelength leads to the formation of a covalent bond with a nearby amino acid side-chain 16 . Almost all amino acid side chains are reactive, as are each of the nucleobases, although uracil cross-links most readily 17 18 19 . Several techniques to study RNA-interaction sites have been developed based on cross-linking, either in cells 20 , or on RNA-protein complexes extracted from them 21 .…”

Ring Opening Photoreactions of Cytosine and Uracil with Ethylamine

“…The potential complexity of irradiated DNA-protein systems is a major challenge to investigators who try to identify the amino acid and nucleobase partners in UV-induced DNA-protein cross-links. Shetlar and coworkers (26)(27)(28) measured the apparent quantum yields for 19 amino acids and selected di-and tripeptides toward photoaddition to DNA and homopolynucleotides of the major DNA and RNA bases. None of the amino acids, when incorporated into a glycyl dipeptide, can be regarded as unreactive in photoaddition to the macromolecules studied in the survey.…”

“…Lysine has been found to be one of the most reactive amino acids toward photoaddition reactions with nucleobases, nucleosides, DNA and polynucleotides (26)(27)(28)(29)(30)(31)(32)(33). It occurs in relatively high abundance in the histones, an important class of structural proteins in eukaryotic chromatin.…”