Self-Assembly of β-Glucosidase and d-Glucose-Tethering Zeolite Crystals into Fibrous Aggregates

Abstract

β-Glucosidase and D-glucose-tethering micrometer-sized zeolite crystals self-assemble into thin (2-20 µm) and very long (>1 cm) fibrous aggregates in water. The process proceeds at a faster rate in a buffer solution of pH 4.8 at which the enzymatic activity is highest. The zeolite and enzyme remain intact within the fibrous material. Furthermore, the enzymatic activity of β-glucosidase is preserved even after they are kept in water for more than 6 months at room temperature. With the zeolite to enzyme weight ratio of 5, all the zeolite crystals are buried within the round fibrils which consist of either a single strand or helical double strands. Upon increasing the ratio to 10, clusters of unburied zeolite crystals appear on the exterior of the fibrils, while narrow flat fibers with smooth surfaces are formed upon decreasing the ratio to 2.5. The process is proposed to initiate by the tight binding between the zeolite-bound D-glucose moieties and β-glucosidase followed by crystallization of the enzyme over the zeolite-bound enzyme monolayer. This report thus reveals a novel behavior of β-glucosidase and demonstrates an unprecedented phenomenon that an enzyme and its substrate-tethering inorganic crystals self-assemble into structured aggregates.

Synthesis, mesomorphic and physical properties of two new analogs of Schiff’s base with an alkenic terminal chains

“…The crude product was purified by recrystallization from acetone/methanol. The chemical structure of the compounds 1a and 1b is similar, as it is presented in [6,[14][15][16][17][18]. The structure of the compounds 1a and 1b were confirmed by various spectroscopic methods.…”

“…The salicylaldimine compounds 1a and 1b were prepared as previously described [14,15] by the p-toluensulfonic acid catalysed condensation of 2-Hydroxy-4-(10-undecenyloxy)benzaldehyde [16] with corresponding aniline in toluene. 2-Hydroxy-4-(10-undecenyloxy)benzaldehyde (5 mmol), 6 mmol of 4-hexylaniline and 4-hexyloxyaniline, respectively, and p-toluensulfonic acid (80 mg) were dissolved in 50 ml toluene.…”

A new liquid crystal of considerable value for the separation of closely related solvents by gas chromatography

“…UMBPIMP has been synthesised by the p-toluenesulfonic acid-catalysed condensation of 2-hydroxy-4-(10-undecenyloxy)benzaldehyde [26] and (S)-4-(2-methylbutoxy)aniline [26] in toluene, and purified by recrystallisation from acetone/methanol. The product has been characterised by the normal spectroscopic methods ( 1 H-, 13 C-NMR, UV-Vis, IR and MS).…”

“…UMBPIMP was synthesised using a well-established procedure [24,25], by p-toluenesulfonic acid (40 mg) catalysed condensation of 2-hydroxy-4-(10-undeceny loxy)benzaldehyde [26] (2.5 mmol) with (S)-4-(2-methylbutoxy)aniline [27] (3 mmol) in toluene (25 ml). The solution was refluxed for 5 h and the product purified by crystallisation from acetone/methanol.…”

Non‐symmetric bent‐core mesogens with one terminal vinyl group

“…Compounds I-n(a) were obtained by etherification of the corresponding bromoalkene (n510 and 11) with methyl 4-hydroxybenzoate with K 2 CO 3 as base, followed by hydrolysis with KOH. Compounds n(a) were obtained by esterification of the acid chlorides of I-n(a) with 4-hydroxybenzaldehyde, IIn(a), followed by NaClO 2 oxidation [29]. End products m-P-n(a) were obtained via carbodiimide esterification of P-m and n(a) [30].…”