DeoxyNAD and deoxyADP-ribosylation of proteins.
Recently, two deoxyribose analogs of beta NAD+ (2'-deoxy and 3'-deoxyNAD+) have been synthesized and purified in this laboratory. Whereas 2'-deoxyNAD+ was an efficient substrate for arg-specific mon(ADP-ribosyl) transferases, it was not a substrate for poly(ADP-ribose) polymerase (PARP). Instead, it was a non-competitive inhibitor of beta NAD+ in the ADP-ribose polymerization reaction catalyzed by PARP. Thus, 2'-deoxyNAD+ has been utilized to distinguish between mono(ADP-ribose) and poly(ADP-ribose) acceptor proteins. 2'-deoxyNAD+ has also been used to characterize the arg-specific mono(2'-deoxyADP-ribosyl)ation reaction of PARP with cholera toxin or avian mono(ADP-ribosyl)transferase. By contrast, 3'-deoxyNAD+ can effectively be utilized as a substrate by PARP. However, while the estimated Km and Kcat of polymerization with 3'-deoxyNAD+ were 20 microM and 0.11 moles/sec, the Km and Kcat with beta NAD+ as a substrate were 59 microM and 1.29 moles/sec, respectively. Determination of the average size of 3'-deoxyADP-ribose polymers indicated that chains no larger than four residues are synthesized with this substrate. Thus, the utilization of 3'-deoxyNAD+ has facilitated the electrophoretic identification of poly(ADP-ribose) acceptor proteins in mammalian chromatin.
Alvarez-Gonzalez
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Department of Microbiology and Immunology, University of North Texas Health Science Center at Fort Worth 76107-2699.
D036002:ADP Ribose Transferases; D000246:Adenosine Diphosphate Ribose / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D015394:Molecular Structure; D009243:NAD / Q000031:analogs & derivatives* / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism*
D002843:Chromatin; D011506:Proteins; D009243:NAD; D000246:Adenosine Diphosphate Ribose; C057676:3'-deoxynicotinamide adenine dinucleotide; C021004:2'-deoxynicotinamide adenine dinucleotide; D036002:ADP Ribose Transferases; D011065:Poly(ADP-ribose) Polymerases