Identification of an active‐site residue in subunit S1 of pertussis toxin by photocrosslinking to NAD

FEBS Letters

Cockle, Stephen A.¹ 

[1] Connaught Centre for Biotechnology Research, 1755 Steeles Avenue West, Willowdale, Ontario M2R 3 T4, Canada

关键词: Pertussis toxin;    Toxin binding;    Photoaffinity labeling;    Crosslinking;    NAD;    PT;    pertussis toxin;    CHAPS;    3-(3-cholamido-propyl)dimethylammoniopropane-1-sulfonate;    SDS-PAGE;    SDS-polyacrylamide gel electrophoresis;    RP-HPLC;    reverse-phase high-performance liquid chromatography;    DTT;    dithiothreitol;    PTH;    phenylthiohydantoin;    DT;    diphtheria toxin;    ET;    P. aeruginosa exotoxin A;    CT;    cholera toxin;   

DOI  :  10.1016/0014-5793(89)80652-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The site of interaction of NAD with the isolated S1 subunit of pertussis toxin was investigated by photoaffinity labelling. When S1 was irradiated at 254 nm in the presence of [carbonyl-¹⁴C]- or [adenine-¹⁴C]NAD, the uptake of radioactivity was equivalent to 0.75 and 0.1 mol/mol respectively, while the NAD glycohydrolase activity was abolished. Inactivation was thus accompanied by crosslinking of the nicotinamide portion of NAD to the protein. Sequence determination of purified radioactive peptides indicated that Glu-129 was a major site of labelling. This residue is therefore closely associated with either NAD binding or hydrolysis.

【 授权许可】

Unknown