Preparation of a new thermo-responsive adsorbent with maltose as a ligand and its application to affinity precipitation

Abstract

A thermo‐responsive polymer on which maltose was covalently immobilized as an affinity ligand was newly synthesized for purification of thermolabile proteins from the crude solution by affinity precipitation. Among the thermo‐responsive polymers synthesized as carriers for adsorbent, poly(N‐acryloylpiperidine)–cysteamine (pAP) has a lower critical solution temperature (LCST) of around 4°C, at which its solubility exhibits a sharp change. Adsorbent for affinity precipitation was prepared by combining pAP with maltose using trimethylamine–borane as a reducing reagent. This adsorbent (pAPM) obtained showed a good solubility response: pAPM in the basal buffer (pH 7.0) became soluble below 4°C and was completely insoluble above 8°C. The affinity precipitation method using pAPM consisted of the following four steps: adsorption at 4°C, precipitation of the complex at 10°C, desorption by adding the desorption reagent at 4°C, and recovery of a target protein at 10°C. In the affinity precipitation of Con A from the crude extract of jack bean meal, 82% of Con A added was recovered with 80% purity by addition of 0.2 M methyl‐α‐D‐mannopyranoside as a desorption reagent. In the repeated purification of Con A from the crude extract, pAPM could be satisfactorily reused without decrease in the affinity performance. Moreover, when pAPM was used for the purification of thermolabile α‐glucosidase from the cell‐free extract of Saccharomyces cerevisiae, 68% of total activity added was recovered and the specific activity per amount of protein of the purified solution was enhanced 206‐fold higher than that of the cell‐free extract without thermal deactivation of the enzyme. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 60: 568–579, 1998.

A pH- and Temperature-Responsive Magnetic Composite Adsorbent for Targeted Removal of Nonylphenol

“…If one combines the benefits of both pH- and thermal- responsiveness to synthesize dual-responsive adsorbents, the materials may have high efficiency for the removal of NP and other contaminants with similar features. To the best of the authors’ knowledge, although there are previous references that demonstrated or predicted that single-responsive materials could be applied for water treatment, such as temperature-responsive − and pH-responsive adsorbents, − few works have studied the dual-responsive ones that are specially designed to adapt the structural characteristics of the contaminant NP.…”

Norfloxacin and Bisphenol-A Removal Using Temperature-Switchable Graphene Oxide

“…Such concerns can be solved by selecting appropriate temperature-responsive polymer chains (both type and chain length) with a suitable LCST to prepare designed temperature-switchable GO. This is feasible because LCST values of different types of temperature-responsive polymer with different chain lengths can be adjusted from 0 to 60 °C. , For instance, without changing the temperature of a large amount of NOR-contaminated water originally at 30 °C, a temperature-switchable GO with a LCST higher than 30 °C can work as an effective hydrophilic adsorbent for the elimination of NOR.…”

“…PNNPAM with carboxyl end groups (PNNPAM-COOH) was prepared according to the reported method . Preliminary experiments and literatures demonstrated that different average repeated unit numbers of a PNNPAM-COOH chain resulted in different LCSTs (Supporting Information Table S1). , Given the temperature range (0–40 °C) of commonly available contaminated water, the PNNPAM-COOH with a LCST of 21 °C (close to the middle of the above range) was selected as a model in further P-GO synthesis for better clarifying the temperature effect. P-GO was fabricated by a “graft-to” method, as illustrated in Figure a.…”

Tunable Thermal‐Sensitive Polymer–Graphene Oxide Composite for Efficient Capture and Release of Viable Circulating Tumor Cells

“…The homopolymers poly( N -acryloyl piperidine) (PAP) and poly( N,N -diethyl acrylamide) (PDEA) have LCSTs of 4°C and 25°C respectively. [36] The required capture/release modulation temperature for the CTC device can be achieved by changing the ratio of the two monomers in the copolymer. For example, a copolymer synthesized with 7:3 molar ratio of AP:DEA showed a critical temperature of around 12–13°C, which was used in this study (Figure 2b).…”