5bni

Publication Abstract from PubMed

Cyclic ADP-ribose (cADPR) mobilizes intracellular Ca(2+) stores and activates Ca(2+) influx to regulate a wide range of physiological processes. It is one of the products produced from the catalysis of NAD(+) by the multifunctional CD38/ADP-ribosyl cyclase superfamily. After elimination of the nicotinamide ring by the enzyme, the reaction intermediate of NAD(+) can either be hydrolyzed to form linear ADPR or cyclized to form cADPR. We have previously shown that human CD38 exhibits a higher preference towards the hydrolysis of NAD(+) to form linear ADPR while Aplysia ADP-ribosyl cyclase prefers cyclizing NAD(+) to form cADPR. In this study, we characterized the enzymatic properties of porcine CD38 and revealed that it has a prominent secondary NAD(+) cyclase activity producing cADPR. We also determined the X-ray crystallographic structures of porcine CD38 and were able to observe conformational flexibility at the base of the active site of the enzyme which allow the NAD(+) reaction intermediate to adopt conformations resulting in both hydrolysis and cyclization forming linear ADPR and cADPR respectively.

Porcine CD38 exhibits prominent secondary NAD(+) cyclase activity.,Ting KY, Leung CF, Graeff RM, Lee HC, Hao Q, Kotaka M Protein Sci. 2016 Mar;25(3):650-61. doi: 10.1002/pro.2859. Epub 2016 Jan 12. PMID:26660500^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.