In:
European Journal of Biochemistry, Wiley, Vol. 117, No. 1 ( 1981-06), p. 161-164
Abstract:
The inhibition constants ( K i ) of DNA‐dependent RNA polymerase B (or II) from calf thymus were measured for eight synthetically obtained bicyclic amanitin‐like thioethers, two R ‐sulfoxides, and two S ‐sulfoxides. These K i values were compared with those of α‐amanitin, its 6′‐ O ‐methylether Ia (an R ‐sulfoxide), the S ‐sulfoxide, the sulfone, the S ‐deoxo derivative (Id) of IA, and several previously described amatoxins. The necessity of a β‐methyl side chain in position 3 and a hydroxy group in proline‐2 was confirmed. Additionally, the presence of an isoleucine side chain in position 6 and the absence of a side chain in position 5 was recognized as important for binding to the enzyme. In the three sulfoxide samples examined, the R ‐diastereomer was found to be a stronger inhibitor than the S ‐form. The contribution of every structural element to biological activity has been discussed.
Type of Medium:
Online Resource
ISSN:
0014-2956
,
1432-1033
DOI:
10.1111/ejb.1981.117.issue-1
DOI:
10.1111/j.1432-1033.1981.tb06315.x
Language:
English
Publisher:
Wiley
Publication Date:
1981
detail.hit.zdb_id:
1398347-7
detail.hit.zdb_id:
2172518-4
SSG:
12
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