Biomedical Engineering Reference
In-Depth Information
A further study revealed that the phosphorylase dosage and
Glc-1-P/primer ratio influenced the reaction rate of the enzymatic
synthesis, presumably by changing the balance between amylose
synthesis and amylose-lipid complexation and precipitation, and
impacted the molecular weight of the complexes [17]. Tailor-made
short-chain amylose-lipid complexes could be produced by choosing
the appropriate reaction conditions. In general, several interactions
between the growing amylose chains and the lipids can be envisaged.
First, enzymatic synthesis and complexation/precipitation occur
rather independently, i.e., resembling classical synthesis (Fig. 10.4a).
Complexation and precipitation would only take place after a longer
amylose chain has been synthesized. It is also possible that amylose
is synthesized around the lipid present, resulting in immediate
complexation, while precipitation only occurs when a sufficient
number of lipids are incorporated in the amylose helix (vine-twining
complexation, Fig. 10.4c).
An intermediate between these two as a way was proposed, in
which amylose-lipid complexes are synthesized semienzymatically
(Fig. 10.4b); elongation of the primer occurs until an amylose chain
is obtained that is sufficiently long to complex at least one lipid
molecule. This complex then stays in the solution and the enzymatic
chain extension of the amylose chain continues, together with the
subsequent complexation, until the formed amylose-lipid complex
becomes insoluble and precipitates.
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