Evidence that amylose synthesis occurs within the …

The vine-twining polymerization using the resulting G7-PTHF was then conducted to synthesize amylose-PTHF as follows (). Frist, G7-PTHF was suspended in sodium acetate buffer (pH 6.2) using an ultrasonic wave. After the addition of G-1-P (100 equiv. for G7-PTHF) and thermostable phosphorylase from VF5, the mixture was stirred vigorously for 48 h at 40-45°C. The precipitated product was collected by filtration, washed with water, acetone, and chloroform, and then dried under reduced pressure at room temperature to obtain the product.

The control of amylose synthesis - ResearchGate

At least in rice the main import into amyloplasts for starch synthesis is  ( et al., 2016).

The requirements for and regulation of the synthesis of amylose

In order to synthesize the amylose-PTHF in the vine-twining polymerization, we designed G7-PTHF as the primer-guest conjugate, and accordingly, synthesized it from G7-N3 and acetylene-terminated PTHF by copper(I)-catalyzed azide-alkyne cycloaddition, click chemistry (); the former was prepared by the literature procedure and the latter was obtained by ring-opening polymerization of tetrahydrofuran by using MeOTf, followed by treatment with sodium propargyl alkoxide. The 1H NMR spectrum of the product in DMSO-6 fully supported the structure of G7-PTHF ().

Improved understanding of rice amylose biosynthesis …

We recently achieved to synthesize a novel supramolecular polymer, which was composed of continuum of the amylose-poly(L-lactide) (PLLA) inclusion complexes, was produced when a G7-functionalyzed PLLA was used as a primer-guest conjugate substrate in the vine-twining polymerization. In this approach, a propagating amylose chain started from G7 moiety in the primer-guest conjugate by the phosphorylase catalysis includes a polyester, PLLA, segment in the other substrate. Such special type of the vine-twining polymerization among the substrates successively takes place, giving rise to the novel inclusion supramolecular polymer composed of amylose and PLLA. This vine-twining polymerization approach for the supramolecular polymer has inspired us to be applicable to other hydrophobic polymers. Because it was found to form the inclusion complex with amylose, in this paper, we employed a polyether, poly(tetrahydrofuran) (PTHF), and demonstrated the synthesis of inclusion supramolecular polymer composed of amylose and PTHF (amylose-PTHF) by means of the vine-twining polymerization using G7-functionalized PTHF (G7-PTHF) as a primer-guest conjugate.

We now report the synthesis of amylose-like materialby another enzyme system from potato.
The system(maltodextrin + D-enzyme + hexokinase + adenosine triphosphate) shouldtherefore bring about amylose synthesis.

Synthesis of amylose by potato D-enzyme.

A new class of rod-coil block copolymers is synthesized by chemoenzymatic polymerization. In the first step, maltoheptaose, which acts as a primer for the synthesis of amylose, is attached to poly(2-vinyl pyridine) (P2VP). The enzymatic polymerization of maltoheptaose is carried out by phosphorylase to obtain amylose-b-P2VP block copolymers. The block copolymer is characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, and wide-angle X-ray scattering techniques. The designed molecules combine the inclusion complexation ability of amylose with the supramolecular complexation ability of P2VP and therefore this kind of rod-coil block copolymers can be used to generate well-organized novel self-assembled structures.

Enzymatic Synthesis and Properties of Highly Branched Rice Starch Amylose and Amylopectin Cluster.

The control of amylose synthesis - INFONA

(a) Synthesis of primer-guest conjugate (G7-PTHF) and (b) vine-twining polymerization using G7-PTHF to produce inclusion supramolecular polymer (amylose-PTHF).

Synthesis of amylose by potato D-enzyme — University …

The XRD pattern of the product () shows two diffraction peaks at 2 = 13° and 20°, which is completely different from that of an enzymatically synthesized amylose (by the phosphorylase-catalyzed enzymatic polymerization), G7-PTHF, and PTHF (), but is similar to that of the standard inclusion complex product from G7 and PTHF as prepared by our literature procedure () . This result strongly suggests that the produced amylose formed inclusion complex with PTHF segment in the conjugate during the progress of the enzymatic polymerization. The 1H NMR spectrum of the product in DMSO-6 () shows both signals at 5.1 and 3.7-3.1 ppm due to amylose (H1 and H2-6, respectively) and methylene signals of PTHF at 3.2 and 1.5 ppm. The intensity ratio of saccharide signals to the PTHF signals from the product was larger compared with that from G7-PTHF (), indicating the success of the phosphorylase-catalyzed enzymatic polymerization. To estimate the included ratio of the PTHF chain to the amylose helix, furthermore, the integrated ratio of the methylene signal b to the H1 signal (b/H1) was calculated to be 0.84 in the case of G-1-P/G7-PTHF = 100, which was relatively close to the b/H1 value, 0.89, in the 1H NMR spectrum of the standard amylose-PTHF inclusion complex reported in our previous literature. This result suggested that the elongated amylose chain fully included PTHF segment.