Elaborate metal-free electrochemiluminescence (ECL) systems require highly robust organic emitters in the radical form. In their Research Article (e202301109), Keishiro Tahara, Masaaki Abe, and co-workers used a classical Lewis acid B(C6F5)3 as an electrochemical protector of donor–acceptor emitters, leading to discovery pairing-induced ECL enhancement. The also converted molecular arrangements...

We report a photochemical method for the chemoselective radical functionalization of tryptophan (Trp)-containing peptides. The exploits photoactivity an electron donor-acceptor complex generated between unit and pyridinium salts. Irradiation with weak light (390 nm) generates intermediates right next to targeted Trp amino acid, facilitating proximity-driven functionalization. This protocol exhi...

A covalent, catalytic intermediate of cytosolic liver acetyl coenzyme A: arylamine N-acetyltransferase (EC 2.3.1.5) from rapid acetylator rabbits (III/J) was isolated and chemically characterized. The active site was further studied using two covalent inhibitors, [2-3H]iodoacetic acid and bromoacetanilide. Inhibition experiments with [2-3H]iodoacetic acid at pH 6.9 showed that the incorporation...

In glacial acetic acid, phthalanilic acid and its monosubstituents are known to be converted to the corresponding phthalimides in relatively good yields. In this study, we computationally investigated the experimentally proposed two-step (addition-elimination or cyclization-dehydration) mechanism at the second-order Møller-Plesset perturbation (MP2) level of theory for the unsubstituted phthala...

An O6-methylguanine-DNA methyltransferase has been partially purified from calf thymus by conventional biochemical techniques. The enzyme was specifically radioactively labelled at the cysteine residue of the active site and further purified by attachment to a solid support. Following digestion with trypsin, a radioactive peptide containing the active site region of the protein was purified by ...

Melittin is a 26-amino acid amphipathic peptide which binds to calmodulin in a calcium-dependent manner. The utility of melittin as a peptide replica of the calmodulin-binding region of calmodulin acceptor proteins (CaMBPs) was investigated. Antibody against melittin was raised and purified by antigen affinity chromatography. Interaction of the antibody with CaMBPs was initially suggested by th...

The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solu...

By immunochemical methods we had presented evidence for a primary acceptor complex for photosystem I of photosynthetic electron transport. During purification of this complex, obtained as a water soluble fraction from ether treated lyophilized chloroplasts, two low molecular fractions are also obtained, which may or may not have relation to the primary acceptor. The purification and identificat...

As part of a study on enzymic catalysis of group transfer, this laboratory has previously reported on the enzymic transfer of the glucuronyl radical from a variety of donor substrates to a number of acceptor alcohols (1). The phenomenon was studied in detail and conditions for efficient group transfer were investigated. The present paper reports the use of a similar approach in studying the aci...

A rapid method for the synthesis of oligodeoxynucleotides (ODNs) terminated by 5'-amino-5'-deoxythymidine is described. A 3'-phosphorylated ODN (the donor) is incubated in aqueous solution with 5'-amino- 5'-deoxythymidine in the presence of N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), extending the donor by one residue via a phosphoramidate bond. Template- directed ligati...