Biomedical Engineering Reference
In-Depth Information
OH
O
O
OH
O
HO
HO
OH
OH
O
2
N
O
OCH
2
CH
2
O
CH
3
n
O
+
O
HO
OH
NH
2
O
OH
3
HO
OH
O
OH
O
HO
HO
OH
O
OH
O
O
OH
HO
OCH
2
CH
2
O
CH
3
n
H
O
OH
3
HO
phosphorylase
Glc-1-P
OH
O
OH
O
HO
HO
OH
O
OH
O
O
OH
HO
OCH
2
CH
2
O
CH
3
n
H
O
OH
m
HO
MPEO-
block
-amylose
Figure 10.2
Synthesis of MPEO-
block
-amylose by phosphorylase-catalyzed
polymerization.
Maltopentaose-
block
-alkyl chain surfactants (C8Glc
, C12Glc
,
5
5
and C16Glc
) were synthesized, where an alkyl group (C8, C12, and
C16) is linked to the reducing end of Glc
5
[13,14]. The primers were
5
lactone with octyl-, dodecyl-, or
hexadecylamine (Fig. 10.3). The primer surfactants formed micelles
in water, which were dissociated upon the phosphorylase-catalyzed
polymerization. The enzymatic polymerization of Glc-1-P using the
primer surfactants was performed in the presence of phosphorylase
b and adenosine 5'-monophosphate sodium salt (AMP) in a
Bis-tris buffer at 40
prepared by the reaction of a Glc
5
C; this enzyme is activated by AMP. By using
the property of the micelle formation of the primer surfactants,
the micelle-to-vesicle transition of the mixed lipid/the primer
systems was caused by the enzymatic polymerization and could be
controlled. Consequently, C12Glc
°
micelles were viewed as enzyme-
responsive molecular assembly systems. An enzyme-responsive
artificial chaperone system using the amphiphilic primer (C12Glc
5
)
as a surfactant and phosphorylase b was designed to enable protein
refolding. Effective refolding of carbonic anhydrase B after both
heat denaturation (70
5
C for 10 min) and guanidine hydrochloride
(6 M) denaturation was observed by controlled association between
the protein molecules and the C12Glc
°
primer micelle through the
5
enzymatic polymerization.
