## 3 Results and Discussion  
For the chemoenzymatic process, we first performed the modification of the maltooligosaccharide primers on the PGA main-chain by condensation reaction of Glc\({}_{7}\)-NH\({}_{2}\) with carboxylate groups of PGA (equimolar feed ratio of amino group to carboxylate group) in water using a condensing agent (EDC/NHS) according to the procedure, reported in our previous publication (Figure 1) [9]. We measured the \({}^{1}\)H NMR spectrum of the isolated material to support the structure of maltooligosaccharide-modified PGA as described in Section 2, where the DS of the primers for a repeating GA unit was calculated by the integrated ratio of the \(\alpha\)-anomeric signal ascribed to maltooligosaccharide at \(\delta\) 5.18 to the \(\alpha\)-methine signal (-C-CH(C=O)-NHC=O) derived from PGA at \(\delta\) 4.10-4.27 to be 5.7%. We then carried out the thermostable GP-catalyzed copolymerization of D-glucal with Glc-1-P as comonomers from the primers on the PGA chain in different feed ratios (entries 2-5 in Table 1) in Tris-acetate buffer (0.20 mol/L, pH 6.9) containing KH\({}_{2}\)PO\({}_{4}\) at 40 \({}^{\circ}\)C for 48 h to synthesize the P2D-amylose-grafted PGAs (Figure 2). The precipitated products were isolated by centrifugation and subsequent lyophilization. We also examined the thermostable GP-catalyzed homopolymerizations of Glc-1-P and D-glucal as a \begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**Entry**} & \multicolumn{2}{c}{**Feed Ratio**} & \multirow{2}{*}{**Yield (\({}^{\text{b}}\)**)**} & \multirow{2}{*}{**Unit Ratio (\({}^{\text{d}}\)**} & \multirow{2}{*}{**DP (\({}^{\text{e}}\)**)**} \\  & **(Primer:D-Glucal:Glc-1-P)** & & & \\ \hline
1 & 1:0:200 & 83.3 & 0:10 & 175.1 \\
2 & 1:200:200 & 58.3 & 2.0:8.0 & 162.1 \\
3 & 1:400:200 & 43.5 & 3.5:6.5 & 149.5 \\
4 & 1:600:200 & 36.1 & 3.6:6.4 & 159.3 \\
5 & 1:1200:200 & 23.7 & 3.8:6.2 & 151.6 \\
6 & 1:200:0 & 12.9 & 10:0 & 16.3 \\ \hline \end{tabular} \({}^{\text{(a)}}\) Reaction was conducted in Tris-acetate buffer containing KH\({}_{2}\)PO\({}_{4}\) at 40 \({}^{\circ}\)C for 48 h. \({}^{\text{(b)}}\) Based on weights of precipitated products and amounts of the total 2 dGlc and Glc residues present in the reaction systems. \({}^{\text{(b)}}\) Determined from integrated ratios of two amoriente signals (\(\alpha\)(1\(\rightarrow\)4)-2 dGlc and \(\alpha\)(1\(\rightarrow\)4)-Glc) in the graft chains to \(\gamma\)-methylene signals (-CH\({}_{2}\)C=O) of the PGA main-chain.  
\end{table} 
Table 1: Thermostable GP-catalyzed (co)polymerization of Glc-1-P, D-glucal/Glc-1-P, or D-glucal from maltooligosaccharide-modified PGA (\({}^{\text{a}}\)). monomer by the same operation to obtain reference materials, that is, the amylose- and 2-deoxyamylose-grafted PGAs, respectively (entries 1 and 6 in Table 1). The \({}^{1}\)H NMR spectra of the copolymerization products, measured in DMSO-\(d_{6}\), detected the characteristic C-2 methylene and \(\alpha\)-anomeric signals assignable to \(\alpha\)(1\(\rightarrow\)4)-2 dGlc units, in addition to the signals derived from the \(\alpha\)(1\(\rightarrow\)4)-Glc and GA units (Figure 3, entry 2 in Table 1), fully supporting the production of the P2D-amylose-grafted PGAs (detailed \({}^{1}\)H NMR data are described in Section 2). The \({}^{1}\)H NMR analysis in NaOD/D\({}_{2}\)O also supported the structures of the amylose- and 2-deoxyamylose-grafted PGAs, obtained by the homopolymerizations of Glc-1-P and D-glucal, respectively (Figures S1 and S2). The 2 dGlc/Glc unit ratios of the P2D-amylose graft chains, which were evaluated from the integrated ratios of the two anomeric signals ascribed to the respective units, were changed according to the D-glucal/Glc-1-P feed ratios (entries 2-5 in Table 1).