CD38 in bovine lung: A multicatalytic NADase.
We report the kinetics and molecular properties of CD38 purified from bovine lung microsomal membranes after its solubilization with Triton X-100. The enzyme was found to be a novel member of a multicatalytic NAD(+)-glycohydrolase (NADase, EC 3.2.2.6). It was able to utilize NAD( + ) in different ways, producing nicotinamide (Nam) and either adenosine diphosphoribose (ADPR, NADase activity) or cyclic ADPR (cADPR, cyclase activity); it also catalyzed the hydrolysis of cADPR to ADPR (cADPR, hydrolase activity). In addition, the enzyme catalyzed the pyridine base exchange reaction with conversion of NAD( + ) into NAD analogues. These data are evidence that CD38 is involved in the regulation of both NAD(+) and calcium-mobilizing agents, the concentration resulting in an essential enzyme that plays a key role in cellular energy and signal-transduction systems.
Polzonetti
Valeria
V
Dipartimento di Scienze Morfologiche e Biochimiche Comparate, Università di Camerino, Italy. valeria.polzonetti@unicam.it
Pucciarelli
Stefania
S
Vita
Alberto
A
Vincenzetti
Silvia
S
Natalini
Paolo
P
D051997:ADP-ribosyl Cyclase 1 / Q000302:isolation & purification* / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007700:Kinetics; D008168:Lung / Q000201:enzymology* / Q000378:metabolism*; D008861:Microsomes / Q000378:metabolism; D009244:NAD+ Nucleosidase / Q000302:isolation & purification* / Q000378:metabolism*
D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1