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1.
Opt Lett ; 45(11): 3058, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32479458

RESUMO

This publisher's note contains corrections to Opt. Lett.45, 2580 (2020).OPLEDP0146-959210.1364/OL.391232.

2.
Opt Lett ; 45(9): 2580-2583, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32356821

RESUMO

Here a continuous axial-spiral phase microplate (CAsPP), based on combining a logarithmic axicon and a spiral phase plate, was proposed for generating high-quality higher-order Bessel vortex beams. The novel optical component implemented via femtosecond laser direct writing possesses compact geometry and unique optical properties. The CAsPP with a diameter of 80 µm possesses a controllable long focus ranging from 50 to 600 µm and exhibits a good self-healing ability after free transmission of about 45 µm. Unique optical properties were demonstrated in both experiments and simulations, which were well matched to each other. This Letter provides new opportunities for applications in integrated optics, optical trapping, laser machining, and information reconstruction.

3.
Biopolymers ; 107(2): 46-60, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27696356

RESUMO

Cel7A from Rasamsonia emersonii is one of the processive endocellulases classified under family 7 glycoside hydrolase. Molecular dynamics simulations were carried out to obtain the optimized sliding and hydrolyzing conformations, in which the reducing ends of sugar chains are located on different sites. Hydrogen bonds are investigated to clarify the interactions between protein and substrate in either conformation. Nine hydrogen bonding interactions are identified in the sliding conformation, and six similar interactions are also found correspondingly in the hydrolyzing conformation. In addition, four strong hydrophobic interactions are also determined. The domain cross-correlation map analysis shows movement correlation of protein including autocorrelation between residues. The root mean square fluctuations analysis represents the various flexibilities of different fragment in the two conformations. Comparing the two conformations reveals the water-supply mechanism of selective hydrolysis of cellulose in Cel7A. The mechanism can be described as follow. When the reducing end of substrate slides from the unhydrolyzing site (sliding conformation) to the hydrolyzing site (hydrolyzing conformation), His225 is pushed down and rotated, the rotation leads to the movement of Glu209 with the interstrand hydrogen bonding in ß-sheet. It further makes Asp211 close to the hydrolysis center and provides a water molecule bounding on its carboxyl in the previous unhydrolyzing site. After the hydrolysis takes place and the product is excluded from the enzyme, the Asp211 comes back to its initial position. In summary, Asp211 acts as an elevator to transport outer water molecules into the hydrolysis site for every other glycosidic bond.


Assuntos
Ascomicetos/enzimologia , Celulases/metabolismo , Proteínas Fúngicas/metabolismo , Simulação de Dinâmica Molecular , Água/química , Sítios de Ligação , Domínio Catalítico , Celulases/química , Proteínas Fúngicas/química , Ligação de Hidrogênio , Hidrólise , Termodinâmica , Água/metabolismo
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