Biology Reference
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its MW. Therefore, the vine-twining polymerization in the presence
of some PTHFs with different average MWs was investigated [4].
The vine-twining polymerization was performed by the
phosphorylase-catalyzed enzymatic polymerization of Glc-1-P from
Glc
in the presence of three PTHFs with different values of
M
and
7
n
M
/
M
(PTHF-1K:
M
and
M
/
M
equal to 1350 and 2.86, respectively;
w
n
n
w
n
PTHF-3K:
M
and
M
/
M
equal to 3040 and 3.13, respectively; and
n
w
n
PTHF-6K:
equal to 6330 and 2.45, respectively) as
the guest polymers in sodium acetate buffer at 40-45
M
and
M
/
M
n
w
n
°
C for 6 h (Fig.
8.4a).
)s of PTHFs included in the cavity
of amylose, PTHFs were extracted from the inclusion complexes
according to the following operation (Fig. 8.4b). After the solutions
of the inclusion complexes in DMSO were stirred at 40
To evaluate
M
s and (
M
/
M
n
w
n
C for 13 h,
they were added to an excess amount of acetone. Then, the acetone
soluble fractions were collected and characterized by
°
1
H NMR
measurements to be PTHFs.
The
M
s and (
M
/
M
)s of the extracted PTHFs were estimated
n
w
n
1
H NMR and GPC measurements, respectively. When PTHF-3K
with
by
equal to 3.13 was employed as the guest polymer for
the vine-twining polymerization,
M
/
M
w
n
M
/
M
of PTHF included in the
w
n
cavity of amylose became narrow (
M
/
M
= 1.46) although its
M
w
n
n
= 3040).
These results indicate that amylose selectively included a specific
range of MWs in PTHF-3K in the vine-twining polymerization. To
investigate the effect of average MWs of the guest PTHFs on the
inclusion behavior of amylose, the vine-twining polymerization
using PTHF-1K and PTHF-6K as the guest polymers was performed.
Consequently, the
(=3590) was almost same as that of the employed one (
M
n
)s of PTHFs included in the cavity
of amylose were almost same as those using PTHF-3K as mentioned
earlier (in the case of using PTHF-1K:
M
s and (
M
/
M
n
w
n
M
and
M
/
M
were equal
n
w
n
to 3120 and 1.41, respectively, and using PTHF-6K:
M
and
M
/
M
n
w
n
were equal to 3700 and 1.74, respectively). Thus, it can be concluded
that, in this polymerization system, amylose selectively includes a
specific range of MWs in PTHFs. These results are probably because
of the difference in the inclusion ability of amylose toward PTHFs
with various MWs in the vine-twining polymerization.
