Calcium inhibition of a heat‐stable cyclic nucleotide phosphodiesterase from Neurospora crassa

FEBS Letters

Shaw, Nicholas M.¹  Harding, Roy W.¹ 

[1] Radiation Biology Laboratory, Smithsonian Institution, 12441 Parklawn Drive, Rockville, MD 20852-1773, USA

关键词: Neurospora crassa;    Cyclic nucleotide phosphodiesterase;    Ca2+ inhibition;    Heat stability;    PMSF;    phenylmethylsulfonyl fluoride;    EGTA;    ethyleneglycol-bis-(β-aminoethyl ether) N;    N′-tetraacetic acid;    TLC;    thin-layer chromatography;   

DOI  :  10.1016/0014-5793(83)80399-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Neurospora crassa had a heat-stable (up to 95°C), soluble cyclic nucleotide phosphodiesterase (PDE). Both unheated and heat-stable PDE activities were inhibited by micromolar concentrations of Ca²⁺. This inhibition was reversed by EGTA or EDTA in molar excess of the Ca²⁺ concentration. Calmodulin was not involved in the Ca²⁺ inhibition, nor was Ca²⁺ inhibition of the heat-stable PDE due to cleavage inactivation of the enzyme by a Ca²⁺-stimulated protease. In addition to Ca²⁺, several other cations inhibited the activity of the heat-stable enzyme. Cyclic AMP and cGMP, but not 2′3′ cAMP were substrates for both unheated and heat-stable PDEs. This is the first report of a PDE which is inhibited by micromolar concentrations of Ca²⁺.

【 授权许可】

Unknown