Biomedical subjects

T Sadatome

Publications and source records attributed to T Sadatome.

2 recordsLinked to original sources

PubMed1990

An attempt to structurally convert mu-selective morphine toward delta-receptor binding: dimerization based on enkephalin conformation.

In order to elucidate the substrate specificities for mu- and delta-opioid receptors, dimerization of the mu-specific morphine molecule was attempted, based on the hypothesis of the possible relationship between the molecular conformation of endogenous enkephalin and its selectivity for each opioid receptor. The NOR2 ([normorphine]N-CH2-CH2-N[normorphine]) thus synthesized exhibited agonist activity showing a preference for binding with the delta-opioid receptor, compared with the parent morphine molecule. Antagonist activity was also observed for NOR3 ([normorphine]N-CH2-CH2-CH2-N[normorphine]).

Animals↗

PubMed1989

Mode of binding of E-64-c, a potent thiol protease inhibitor, to papain as determined by X-ray crystal analysis of the complex.

The three-dimensional structure of the E-64-c-papain complex has been determined by X-ray crystal analysis at 2.5 A resolution (conventional R = 26.9%). The structure determined indicates that: (i) the C2 atom of the oxirane ring of E-64-c is covalently bound by the S gamma atom of Cys-25 of papain; (ii) this covalent bond formation results in a configurational conversion of the oxirane C2 atom from the S- to the R-form; and (iii) extensive hydrogen bonding and hydrophobic interactions are responsible for the specific interaction of the E-64-c molecule with papain.

Binding Sites↗