An endonuclease partially purified from human lymphoblasts, and active against ultraviolet-irradiated DNA, was found to act additionally on DNA damaged by either x-radiation or methylmethanesulfonate. To determine if these activities were truly endonucleolytic, the reaction products were analyzed under conditions that prevented conversion of apurinic or apyrimidinic sites to single-strand break...

Three isotoxins (SP I-III) of the ,-bungarotoxin family were purified to homogeneity via a series of isolation procedures including a final step of h.p.l.c. on an SP column washed with a linear gradient of 0.2-0.6 M sodium acetate at pH 7.4. Their proportions varied greatly with the batch ofvenom. Each isotoxin was demonstrated by SDS/PAGE to contain a phospholipase A2 subunit and a non-phospho...

Alkylpurine glycosylase D (AlkD) exhibits a unique base excision strategy. Instead of interacting directly with the lesion, the enzyme engages the non-lesion DNA strand. AlkD induces flipping of the alkylated and opposing base accompanied by DNA stack compression. Since this strategy leaves the alkylated base solvent exposed, the means to achieve enzymatic cleavage had remained unclear. We dete...

Investigating the alkylation and acylation of N-acylthiazolidinethione, the desired α-alkylated products and C-acylated products are not obtained, but rather the S-alkylated products and O-acylated products are obtained. The possible mechanism proposed shows that the deprotonation agent and electrophilic species are responsible for the stability of enolates. The enolates derived from N-acylthia...