Figure 3.
Figure 3. Structural formulas of some human BVR-B substrates and
inhibitors. a, FMN is a BVR-B substrate, lumichrome an
inhibitor. b, Tetrapyrrole biliverdin IX ,
mesobiliverdin IV and
12-ethyl-13-methyl-mesobiliverdin IV are
substrates; biliverdin IX is
an inhibitor. The formation of a bilirubin isomer results from
the reduction of C10 of the corresponding biliverdin (numbering
as indicated for biliverdin IX ,
which is conserved for the bilatriene skeleton in all other
isomers). The ring nomenclature for all -isomers
is that shown for biliverdin IX .
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nat Struct Biol
(2001,
8,
215-220)
copyright 2001.
,
mesobiliverdin IV 
,
which is conserved for the bilatriene skeleton in all other
isomers). The ring nomenclature for all