12 research outputs found
<b>Kinetic parameters of HAase-</b><b><i>B</i></b><b> towards HA and CSA.</b>
<p><b>Kinetic parameters of HAase-</b><b><i>B</i></b><b> towards HA and CSA.</b></p
<b>Substrate specificity of HAase-</b><b><i>B.</i></b>
a<p>The activities of HAase-<i>B</i> on various substrates were measured as described in materials and methods. The activity of HAase-<i>B</i> on sodium hyaluronate was taken as 100%. The data represent the mean of three experimental repeats with SD≤5%.</p
<b>Purification of the hyaluronidase produced by </b><b><i>Bacillus</i></b><b> sp. A50.</b>
<p><b>Purification of the hyaluronidase produced by </b><b><i>Bacillus</i></b><b> sp. A50.</b></p
SDS-PAGE of hyaluronidase (HAase-<i>B</i>) after Superdex 200 column chromatography.
<p>Marker: Unstained Protein Molecular Weight Marker; Lane 1: supernatant of culture fluid; Lane 2: purified hyaluronidase (HAase-<i>B</i>).</p
Effects of temperature and pH on the activity and stability of HAase-<i>B</i>.
<p>(A) Effect of temperature on HAase-<i>B</i> activity. The activity of HAase-<i>B</i> was measured at different temperatures. (B) Thermal stability of HAase-<i>B</i>. The residual activity was assayed in phosphate buffer (pH 6.0) at 42°C. (C) Effect of pH on HAase-<i>B</i> activity. The activity was measured at 42°C in a broad pH range buffer as described previously. (D) pH stability of HAase-<i>B</i>. Residual activities after incubation at various pH buffer solutions for 1 h or 2 h were assayed at pH 6.0 and 42°C. The graph shows data from triplicate experiments (mean ± SD).</p
Enzymatic reaction kinetics of HAase-<i>B</i> towards HA and CSA.
<p>(A) Time dependent kinetics of HAase-<i>B</i> in digesting HA substrate of various concentrations. (B) The Lineweaver–Burk double reciprocal plot showing 1/V<sub>0</sub> versus 1/[S] (R<sup>2</sup> = 0.9950), V<sub>0</sub> represents initial reaction rate, and [S] represents HA substrate concentration. (C) Time dependent kinetics of HAase-<i>B</i> in digesting CSA substrate of various concentrations. (D) The Lineweaver–Burk double reciprocal plot showing 1/V<sub>0</sub> versus 1/[S] (R<sup>2</sup> = 0.9980), herein, V<sub>0</sub> represents initial reaction rate, and [S] represents CSA substrate concentration.</p
Morphological images of Strain A50.
<p>(A) Transparent zones appeared around some colonies on a HA agar plate after soaked in 2 M acetic acid; (B) Gram staining of strain A50 after being cultured for 12 h, showing rod shaped and gram-positive bacteria under the microscope (Magnification is 15Ă—100); (C) Gram staining of strain A50 after being cultured for 24 h, showing spores under the microscope (Magnification is 15Ă—100).</p
Diversity-Oriented Enzymatic Modular Assembly of ABO Histo-blood Group Antigens
Enzymatic
synthesis of all 15 naturally occurring human ABH antigens
was achieved using a diversity-oriented enzymatic modular assembly
(EMA) strategy. Three enzyme modules were developed, each one-pot
multienzyme module comprises a glycosyltransferase and one or two
corresponding sugar nucleotide generating enzyme(s). These multienzyme
cascade processes provide an efficient and convenient platform for
collective synthesis of all 15 ABH antigens in three operationally
simple steps from five readily available disaccharide acceptors and
three simple free sugars as donor precursors
Chemoenzymatic synthesis of tumor-associated antigen N3 minor octasaccharide
<p></p> <p>A highly efficient chemoenzymatic approach was developed for the preparative scale synthesis of complex tumor-associated antigen N3 minor octasaccharide. The success of this approach relies on the highly efficient one-pot multi-enzyme based sequential enzymatic elongation of a chemically synthesized branched tetrasaccharide core structure.</p
Regioselective One-Pot Benzoylation of Triol and Tetraol Arrays in Carbohydrates
Protection of 2,3,4-<i>O</i>-unprotected α-galacto-
and α-fucopyranosides with BzCN and DMAP/DIPEA as the base afforded
directly and regioselectively the 3-<i>O</i>-unprotected
derivatives. The rationale for these studies was to take advantage
of the eventual cooperativity of the “cyanide effect”
and “the alkoxy group mediated diol effect”. This way,
even the totally unprotected α-galactopyranosides could be regioselectively
transformed into the corresponding 2,4,6-<i>O</i>-protected
derivatives. The great utility of these building blocks was demonstrated
in efficient trisaccharide syntheses