The Chl a Carboxylic Biosynthetic Routes: Reactions Between Mg-Protoporphyrin IX and Protochlorophyllide a - Chlorophyll Biosynthesis and Technological Applications - page 205

Fig. 7.10 DV Mg-Proto
monomethyl ester
(DV Mpe)
7.2.1.1 The Divinyl Mpe Pool
Divinyl Mg-Proto monomethyl ester has two vinyl groups at positions 2 and 4 of the
tetrapyrrole macrocycle (Fig. 7.10 ). The DV nature of the DVMg-Proto monomethyl
ester component of the Mg-Proto monomethyl ester pool of higher plants was
determined by chemical derivatization coupled to analytical fluorescence spectros-
copy at 77 K (Belanger and Rebeiz 1982 ).
Biosynthetic Heterogeneity of DV Mpe in LDV-DDV-LDDV Plants Species
In Fig. 7.11 , Three DV Mpe pools are depicted to be formed in three different
thylakoid environments. The assignment of three DV Mpe biosynthetic pools to
three different thylakoid locations is based on the detection of multiple resonance
excitation transfer bands between Mp(e) and various Chl-protein complexes
(Table 6.1 , Chap. 6 ) and considerations related to the biosynthesis of DV and MV
Pchlide a which will be discussed later.
It is unclear at this stage whether the spatial biosynthetic heterogeneity of DVMpe
is accompanied by chemical biosynthetic heterogeneity or not. In other words, it is
unclear whether the proposed biosynthesis of DV Mpe from DV Mg-Proto via routes
1, 0, and 8 is catalyzed by identical SAMMT or by different SAMMT isozymes.
Biosynthetic Heterogeneity of DV Mpe in LMV-DDV-LDMV Plants Species
In Fig. 7.12 , four DV Mpe pools are depicted to be formed in four different
thylakoid environments. The assignment of four DV Mpe biosynthetic pools to
four different thylakoid locations is based on the detection of multiple resonance
excitation transfer bands between Mp(e) and various Chl-protein complexes
(Table 6.1 , Chap. 6 ) and considerations related to the biosynthesis of DV Pchlide
a which will be discussed later.
It is unclear at this stage whether the spatial biosynthetic heterogeneity of DV
Mpe in DMV-LDV-LDMV plant species is accompanied by chemical biosynthetic
heterogeneity or not. In other words, it is unclear whether the proposed biosynthesis
of DVMpe from DVMg-Proto via routes 10, 11, 0 0 , and 13 is catalyzed by identical
SAMMT or by different SAMMT isozymes.