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MXene-based functional textiles have been widely studied and applied in many fields. However, the service stability of MXene combined with textile substrates in the environment is far from ideal, which makes its practical application a great challenge. Here we introduced gallic acid (GA), as natural reactive polyphenol compound to silk fibers through enzymatic polymerization, which significantly improved the durability of its conductivity. The small molecules of GA can covalently bind to the titanium atoms on the MXene nanosheets, and the tyrosine residues from silk fibroins can be enzymatically oxidized by horseradish peroxidase (HRP) and further coupled with GA simultaneously, thus forming a covalent cross-linked network on the fiber surfaces. Furthermore, the durable MXene-based textile was used to manufacture smart dual-driven thermal devices with temperature monitoring, which can judge the real-time temperature during heating by changes in its apparent color. More importantly, the textile with smart temperature visualization also offers good EMI shielding and superior UV resistance, while retaining its inherent moisture-wicking, breathable and softness. The present work provides a new insight for the preparation of MXene-based multifunctional textile, and the smart visualization of dual-driven heating shows promising applications in practical personal thermal management. [Display omitted] • Enzymatic polymerization realizes the gallic acid (GA)-bridged attachment of MXene to the textile surface. • Conductivity stability and antioxidant properties of the MX@GA covalently-grafted textile are improved. • Smart textile can visualize real-time temperature monitoring while realizing electricity or solar heating. • Smart textile achieves multifunction while retaining their inherent breathable and softness properties. [ABSTRACT FROM AUTHOR]

A rapid and efficient enzymatic procedure for the preparation of an immobilized β-galactosidase has been described. In a first step, soybean peroxidase was used to catalyze the polymerization of a strategically activated phenol ( N –Succinimidyl 3–(4–hydroxyphenyl)propionate, known as Bolton-Hunter reagent). The phenolic support was directly employed for immobilizing β–galactosidase from Bacillus circulans (ATCC 31382, β–Gal–3), giving rise to a new biocatalyst subsequently applied in the synthesis of a β–galatodisaccharide (Gal–β(1–3)–GlcNAc and Gal–β(1–3)–GalNAc). The reaction proceeded with high conversion rates and total regioselectivity. Reusability assays were performed with the same reaction conditions finding that the immobilized enzyme retains about 55% of its activity after eight batches. Finally and based on our results, the two-step enzymatic procedure presented here is a good and green alternative to the preparation of carbohydrates with biological activities. [ABSTRACT FROM AUTHOR]

In this study, we investigated chmemoenzymatic synthesis of amylose-grafted poly(γ-glutamic acid) (PGA) as a new artificial saccharide-peptide conjugate composed of two biological macromolecules. Maltooligosaccharide as a primer of enzymatic polymerization by phosphorylase catalysis was first introduced on the PGA main chain by the condensation reaction using the condensing agent in NaOH aq. Thermostable phosphorylase-catalyzed enzymatic polymerization of α- d -glucose 1-phosphate (G-1-P) as a monomer was then performed from the primer chain ends of the product to obtain amylose-grafted PGAs, which formed hydrogels in reaction media depending on the G-1-P/primer feed ratios. The powder X-ray diffraction patterns of lyophilized samples (cryogels) from the hydrogels suggested that the amylose graft chains formed double helixes, which acted as cross-inking points for self-assembling hydrogelation. The scanning electron microscopic images of the cryogels showed regularly controlled porous morphologies. Moreover, pore sizes of the cryogels increased with increasing the G-1-P/primer feed ratios, whereas the degrees of substitution of primer on the PGA main chain did not obviously affect pore sizes. [ABSTRACT FROM AUTHOR]

Abstract: Novel mutant enzymes of endoglucanase II (EGII) from fungus Trichoderma viride were prepared and their hydrolysis and enzymatic polymerization activities were studied. EGII(core)2 and EGII(core)2-His, which possess sequential two active sites of EGII with a His-tag probe at the N-terminal and with His-tag probes at the N and C terminals, respectively, showed higher hydrolysis activities than EGIIcore with a single active site even in comparison on the active-site concentration basis. These mutant enzymes were applied to the enzymatic polymerization to afford artificial cellulose. The polymerization rates with using EGII(core)2 and EGII(core)2-His were also higher than that with using EGIIcore. The polymerization products were identified as highly crystalline cellulose of type II. The mutant enzymes were also effective to prepare spherulites. EGII(core)2 and EGII(core)2-His are considered to possess higher hydrolysis and polymerization activities than EGIIcore mainly due to the suitably stabilized conformation with the sequential arrangement. [Copyright &y& Elsevier]