nicotinamide article 6 PARP 4 catalysis 4 enzyme activity 4 nicotinamide adenine dinucleotide adenosine diphosphate ribosyltransferase 4 nonhuman 4 theophylline 4 thymidine 4 3 aminobenzamide 2 Animals 2 Base Sequence 2 Cloning, Molecular 2 Colorimetry 2 Colorimetry—analysis, niacinamide in multicomponent vitamin preparations 2 Crithidia fasciculata 2 D,L-dithiothreitol 2 DNA 2 DNA Damage 2 DNA Repair 2 DNA damage 2 DNA repair signalling 2 DNA topoisomerase 2 DNA topoisomerase I 2 DTT 2 Electrophoresis, Polyacrylamide Gel 2 Enzyme Activation 2 Escherichia coli 2 Eukaryota 2 Gene Expression 2