Glycoside hydrolase family 13 contains exo-glucosidases specific for α-(1→4)- and α-(1→6)-linkages including α-glucosidase, oligo-1,6-glucosidase, and dextran glucosidase. The α-(1→6)-linkage selectivity of Streptococcus mutans dextran glucosidase was altered to α-(1→4)-linkage selectivity through site-directed mutations at Val195, Lys275, and Glu371. V195A showed 1300-fold higher kcat/Km for maltose than wild-type, but its kcat/Km for isomaltose remained 2-fold higher than for maltose. K275A and E371A combined with V195A mutation only decreased isomaltase activity. V195A/K275A, V195A/E371A, and V195A/K275A/E371A showed 27-, 26-, and 73-fold higher kcat/Km for maltose than for isomaltose, respectively. Consequently, the three residues are structural elements for recognition of the α-(1→6)-glucosidic linkage.
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http://dx.doi.org/10.1016/j.febslet.2015.02.023 | DOI Listing |
Proc Natl Acad Sci U S A
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Experimental Physics V, Department of Physics, University of Bayreuth, D-95447 Bayreuth, Germany.
Photosynthetic microbes have evolved and successfully adapted to the ever-changing environmental conditions in complex microhabitats throughout almost all ecosystems on Earth. In the absence of light, they can sustain their biological functionalities through aerobic respiration, and even in anoxic conditions through anaerobic metabolic activity. For a suspension of photosynthetic microbes in an anaerobic environment, individual cellular motility is directly controlled by its photosynthetic activity, i.
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January 2025
Federal Research Centre «Fundamentals of Biotechnology», Russian Academy of Sciences, Moscow, Russia, 119071.
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View Article and Find Full Text PDFPlant Cell Rep
January 2025
School of Life Science, Anhui Agricultural University, Hefei, 230036, China.
SmbHLH93can activate the expression of SmCHS, SmANS, SmDFR and SmF3H.Overexpression of SmbHLH93promotes anthocyanin biosynthesis. SmbHLH93can interact with SmMYB1 to promote anthocyanin accumulation.
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January 2025
College of Materials Science and Engineering, Key Laboratory of Advanced Functional Materials, Ministry of Education of China, Beijing University of Technology, Beijing 100124, China.
To address the demands of rapidly advancing precision instruments requiring higher efficiency and miniaturization, permanent magnets must exhibit exceptional energy density, temperature stability, high magnetic energy product [()], and adequate coercivity (). Herein, we design rare earth Er-based magnets (2 : 17-type Er-magnets) with a composition of (Er, Sm)(Co, Fe, Cu, Zr). Erbium-based compounds (ErCo) offer a unique combination of temperature compensation and high saturation magnetization compared to other heavy rare earth elements, resulting in 2 : 17-type Er-magnets with superior temperature stability in and ().
View Article and Find Full Text PDFLuminescence
January 2025
Department of Display Science and Engineering, Pukyong National University, Busan, Republic of Korea.
The influence of Eu concentration on the crystal structure and photoluminescence (PL) properties of Ca(PO):xEu (0.06 ≤ x ≤ 0.10) phosphors is systematically investigated using X-ray diffraction (XRD) Rietveld refinement, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, UV-visible spectroscopy, and PL spectroscopy.
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