Amino Acid‐Dependent Host–Guest Interaction: Polyglycerol Dendrimer of Generation 3 Encapsulates Amino Acids Bearing Two Amino Groups

Abstract

Ap olyglycerol dendrimer (PGD), which is known as ab iocompatible compound,w as demonstrated as ah ost molecule for aminoa cids. PGD of generation 3( PGD-G3) was found to interactw ith basic a-aminoa cids such as l-arginine (Arg) and l-lysine (Lys) in water.The resultsofi sothermal titration calorimetry, 1 HNMR, and 1 H-1 HN OESY NMR measurements revealed that two basic groups in a-amino acids were essential for encapsulationb yP GD-G3. An increase in the pK a value of the amino acid side chains (Arg > Lys > His > Glu) increased the binding constant,t hus suggesting that the basicity of a-aminoa cids is an important factor to interact with ether oxygen of PGD-G3. The results demonstrate the utility of PGD-G3t oward incorporationo f a-amino acids, peptides, and basic proteinsinw ater.

A Supramolecular Hydrogel Based on Polyglycerol Dendrimer‐Specific Amino Group Recognition

“…Unlike HPGs, PGDs exhibit well‐defined nanostructures with narrow molecular weight distributions, resulting in higher reactivity and loading efficiency compared to other molecules . In our previous study, we found that a generation 3 PGD (PGD‐G3) specifically interacted with amino groups of l ‐arginine in aqueous solution . Therefore, one can imagine that the amino group of chitosan may interact with PGDs, enabling us to form a PGD‐based hydrogel.…”

“…A 1 H NMR spectrum of the PGD‐G3/GC hydrogel (Figure S4 c) shows that the peak attributed to the proton next to an amino group of GC, H a ( δ =2.54 ppm, Figure S4 b), was split and shifted to H a“ and H a‘ ( δ =2.59 and 2.74 ppm). The observed peak splitting to H a“ and H a‘ indicates an interaction between PGD‐G3 and GC similar to that described in a previous report: PGD‐G3 formed a complex with basic amino acids in aqueous media . To confirm the amino group recognition, we mixed PGD‐G3 with different types of polysaccharides without amino groups (dextran (Dex), carboxymethyl cellulose (CMC), and hyaluronic acid (HA): Figure S5).…”

“…Another specific property of the PGD‐based hydrogels is l ‐arginine selectivity as PGD‐G3 interacts strongly with l ‐arginine . The l ‐arginine responsive properties of the dried PGD‐G3/GC 3 are shown in Figure a.…”

Temperature-induced recovery of a bioactive enzyme using polyglycerol dendrimers: correlation between bound water and protein interaction

“…1) are dendrimers comprising glycerol units, which along with hyperbranched polyglycerols (HPGs) have been extensively studied for biomedical applications [19,20,21,22,23,24,25,26,27]. Unlike HPGs, PGDs are branched molecules with defined molecular weights [28] and thus support host-guest interactions in a stoichiometric manner [29,30,31,32]. We have focused on PGDs as biomaterials rather than HPGs because of their perfect dendrimer characteristics: the degree of branching (DB) of PGDs is 100%, whereas that of HPGs is 50-60% [19].…”