The strong interaction of hexa-histidine fusion proteins with metal chelate adsorbents was utilized to immobilize beta-galactosidase with a hexa-histidine peptide at the N-terminus to the Ni(2+)-nitrilotriacetic acid adsorbent. The fusion protein was cloned and expressed in Escherichia coli. The purified soluble fusion protein showed the same specific activity as the purified beta-galactosidase and retained 64 percent of its beta-galactosidase activity when bound to the adsorbent. To demonstrate the potential of the immobilized beta-galactosidase in organic chemistry, allyl-beta-D-galactosidase was synthesized from lactose and allyl alcohol on a gram scale. The same enzyme preparation was reused in three subsequent batches to prepare the model compound with high yield.
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http://dx.doi.org/10.1002/bit.260420205 | DOI Listing |
J Am Chem Soc
January 2025
Institute of Organic Chemistry, University Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany.
In ion-pair catalysis, the last intermediate structures prior to the stereoselective transition states are of special importance for predictive models due to the high isomerization barrier between - and -substrate double bonds connecting ground and transition state energies. However, in prior experimental investigations of chiral phosphoric acids (CPA) solely the early intermediates could be investigated while the key intermediate remained elusive. In this study, the first experimental structural and conformational insights into ternary complexes with CPAs are presented using a special combination of low temperature and relaxation optimized N HSQC-NOESY NMR spectroscopy to enhance sensitivity.
View Article and Find Full Text PDFMonatsh Chem
December 2023
Institute of Applied Synthetic Chemistry, TU Wien, Vienna, Austria.
Unlabelled: In recent years, sugar alcohols have gained significant attention as organic phase change materials (PCMs) for thermal energy storage due to their comparably high thermal storage densities up to 350 J/g. In a computational study, outstandingly high values of up to ~ 450-500 J/g have been postulated for specific higher-carbon sugar alcohols. These optimized structures feature an even number of carbon atoms in the backbone and a stereochemical configuration in which all hydroxyl groups are in an 1,3--relationship, as found in the natural hexitol d-mannitol.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Institute of Inorganic Chemistry (IAC), Karlsruhe Institute of Technology (KIT) Engesserstraße 15 D-76131 Karlsruhe Germany
Pt-CeO nanosponges (1 wt% Pt) with high surface area (113 m g), high pore volume (0.08 cm g) and small-sized Pt nanoparticles (1.8 ± 0.
View Article and Find Full Text PDFChem Sci
January 2025
Department of Chemistry, Centre for Atomic Engineering of Advanced Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Anhui University Hefei Anhui 230601 China
Controlling symmetrical or asymmetrical growth has allowed a series of novel nanomaterials with prominent physicochemical properties to be produced. However, precise and continuous size growth based on a preserved template has long been a challenging pursuit, yet little has been achieved in terms of manipulation at the atomic level. Here, a correlated silver cluster series has been established, enabling atomically precise manipulation of symmetrical and asymmetrical surface structure expansions of metal nanoclusters.
View Article and Find Full Text PDFChem Sci
December 2024
Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford South Parks Road Oxford OX1 3QR UK
The reaction chemistry of an unprecedented 'inorganic cumulene' - featuring a five-atom BNBNB chain - towards C[double bond, length as m-dash]O (and related) multiple bonds is disclosed. In marked contrast to related all-carbon systems, the intrinsic polarity of the BNBNB chain (featuring electron-rich nitrogen and electron-deficient boron centres) enables metathesis chemistry with electrophilic heteroallenes such as CO and with organic carbonyl compounds. Transfer of the borylimide unit to [CO], [CS], [PP{(NDippCH)}] and [C(H)Ph] moieties generates (boryl)N[double bond, length as m-dash]C[double bond, length as m-dash]X systems (X = O, S, PP{(NDippCH)}, C(H)Ph), driven thermodynamically by B-O bond formation.
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