Enzyme properties of Aplysia ADP-ribosyl cyclase: comparison with NAD glycohydrolase of CD38 antigen.
An ecto-enzyme of NAD glycohydrolase (NADase) induced by retinoic acid in HL-60 cells is attributed to the molecule of CD38 antigen [Kontani, K., Nishina, H., Ohoka, Y., Takahashi, K., and Katada, T. (1993) J. Biol. Chem. 268, 16895-16898]. CD38 antigen has an amino acid sequence homologous to Aplysia ADP-ribosyl cyclase which generates cyclic adenosine diphosphoribose (cADPR) and nicotinamide (NA) from beta-NAD+. On the basis of this sequence homology, we compared enzyme properties between CD38 NADase expressed as a fusion protein in Escherichia coli and ADP-ribosyl cyclase purified from the ovotestis of Aplysia kurodai. 1) beta-NAD+ analogs, nicotinamide 1, N6-ethenoadenine dinucleotide, and nicotinamide hypoxanthine dinucleotide, did not serve as good substrates for the ADP-ribosyl cyclase, suggesting that the intact adenine ring of beta-NAD+ was required for the cyclase-catalyzed reaction. On the other hand, CD38 NADase utilized the NAD analogs to form ADP-ribose and NA. 2) Kinetic analyses of the ADP-ribosyl cyclase reaction revealed that NA was first released from the substrate (beta-NAD+)-enzyme complex, followed by the release of another product, cADPR, which was capable of interacting with the free enzyme. 3) The enzyme reaction catalyzed by the ADP-ribosyl cyclase was fully reversible; beta-NAD+ could be formed from cADPR and NA with a velocity similar to that observed in the degradation of beta-NAD+. However, CD38 NADase did not catalyze the reverse reaction to form beta-NAD+ from ADP-ribopase and NA. 4) The CD38 NADase activity was, but the ADP-ribosyl cyclase activity was not, inhibited by dithiothreitol.(ABSTRACT TRUNCATED AT 250 WORDS)
Inageda
K
K
Department of Life Science, Tokyo Institute of Technology, Yokohama.
Takahashi
K
K
Tokita
K
K
Nishina
H
H
Kanaho
Y
Y
Kukimoto
I
I
Kontani
K
K
Hoshino
S
S
Katada
T
T
D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000737:chemistry*; D000943:Antigens, Differentiation / Q000737:chemistry*; D000954:Antigens, Surface / Q000737:chemistry*; D001048:Aplysia / Q000201:enzymology*; D002384:Catalysis; D004790:Enzyme Induction; D006066:Gonads / Q000201:enzymology; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases / Q000737:chemistry*; D009244:NAD+ Nucleosidase / Q000096:biosynthesis / Q000737:chemistry*; D009536:Niacinamide / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014212:Tretinoin
D015703:Antigens, CD; D000943:Antigens, Differentiation; D000954:Antigens, Surface; D009536:Niacinamide; D014212:Tretinoin; D009699:N-Glycosyl Hydrolases; D036541:ADP-ribosyl Cyclase; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1