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W Leuzinger

Publications and source records attributed to W Leuzinger.

10 recordsLinked to original sources
PubMed1971

The number of catalytic sites in acetylcholinesterase.

By using two methods of titration, the number of active sites in acetylcholinesterase was determined. Either stepwise inhibition of the enzyme by an irreversible inhibitor, namely di-isopropyl phosphorofluoridate, or direct measurement of the concentration of active sites by titration with o-nitrophenyl dimethylcarbamate yielded an equivalent weight of approx. 130000 for an active site in acetylcholinesterase. This indicates two sites per molecule, since the native enzyme has a molecular weight of 260000.

Acetylcholinesterase↗
PubMed1969

On the association of tyrocidine with acetylcholinesterase.

In studies of several polypeptide antibiotics with a high affinity for a variety of biological membranes, tyrocidine was found to bind specifically to acetylcholinesterase, an enzyme localized in excitable membranes. Several other polypeptides tested were not bound. Tyrocidine reversibly inhibits acetylcholinesterase formed by homogeneous protein, but seems to have no effect on the activity of the enzyme bound to the eel electroplax membrane. This inhibition is accompanied by a reversible association of the soluble enzyme in to ordered and rapidly sedimenting aggregates of large molecular weight. Electron micrographs of acetylcholinesterase are shown which are consistent with the chemical evidence of the existence of four subunits.

Animals↗