Cockle S A
Connaught Centre for Biotechnology Research, Willowdale, Ontario, Canada.
FEBS Lett. 1989 Jun 5;249(2):329-32. doi: 10.1016/0014-5793(89)80652-0.
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.
通过光亲和标记研究了烟酰胺腺嘌呤二核苷酸（NAD）与百日咳毒素分离的S1亚基的相互作用位点。当在[羰基-¹⁴C]-或[腺嘌呤-¹⁴C]NAD存在下，S1在254nm处照射时，放射性摄取量分别相当于0.75和0.1摩尔/摩尔，而NAD糖水解酶活性被消除。因此，失活伴随着NAD的烟酰胺部分与蛋白质的交联。纯化的放射性肽的序列测定表明，Glu-129是主要的标记位点。因此，该残基与NAD结合或水解密切相关。
