Limits...
Functional and structural properties of a novel cellulosome-like multienzyme complex: efficient glycoside hydrolysis of water-insoluble 7-xylosyl-10-deacetylpaclitaxel.

Dou TY, Luan HW, Ge GB, Dong MM, Zou HF, He YQ, Cui P, Wang JY, Hao DC, Yang SL, Yang L - Sci Rep (2015)

Bottom Line: This cellulosome-like multienzyme complex has a novel structure distinct from the well-documented ones.The key catalytic subunit responsible for the β-xylosidase activity against 10-DAXP is identified to be a novel protein, indicating a new glycoside hydrolase (GH) family.The pioneering work described here offers a novel nanoscale biocatalyst for the production of biofuels and chemicals from renewable plant-based natural resources.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.

ABSTRACT
Cellulosome is a kind of multienzyme complex that displays high activity, selectivity, and stability. Here, we report a novel, non-cellulolytic, cellulosome-like multienzyme complex that produced by the Cellulosimicrobium cellulans wild-type strain F16 isolated from soil microflora. This multienzyme complex, with excellent catalytic efficiency of kcat 13.2 s(-1) to remove the C-7 xylosyl group from 7-xylosyl-10-deacetylpaclitaxel (10-DAXP), has an outstanding tolerance against organic solvents and an excellent general stability, with the long half-life of 214 hours. This cellulosome-like multienzyme complex has a novel structure distinct from the well-documented ones. The key catalytic subunit responsible for the β-xylosidase activity against 10-DAXP is identified to be a novel protein, indicating a new glycoside hydrolase (GH) family. The pioneering work described here offers a novel nanoscale biocatalyst for the production of biofuels and chemicals from renewable plant-based natural resources.

No MeSH data available.


Related in: MedlinePlus

Optimum conditions for the hydrolysis of the C-7 xylosidic bond of DAXP.(a) Effect of pH, (b) metal ions and (c) the concentration of calcium on the 10-DAXP xylosidase activity of the purified multienzyme complex Xyl_I, and the key catalytic subunit Xyl_S isolated from it. (d) Xyl_I, and (e) Xyl_S, response surface analysis concerning the effect of reaction temperature and proportion of saturated methanol solutions on the desired activity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4562250&req=5

f2: Optimum conditions for the hydrolysis of the C-7 xylosidic bond of DAXP.(a) Effect of pH, (b) metal ions and (c) the concentration of calcium on the 10-DAXP xylosidase activity of the purified multienzyme complex Xyl_I, and the key catalytic subunit Xyl_S isolated from it. (d) Xyl_I, and (e) Xyl_S, response surface analysis concerning the effect of reaction temperature and proportion of saturated methanol solutions on the desired activity.

Mentions: To determine the optimal conditions for the hydrolysis of 10-DAXP to 10-DAP, single factors such as temperature, pH, cosolvents, and metal ions were initially investigated. The results showed that DMSO, DMF, and methanol were possible cosolvents for the above hydrolysis reaction. Considering the effects on enzyme activities, methanol was preffered for this reaction (Supplementary Table 2), particularly for the kinetic analysis of the purified enzymes against 10-DAXP. Within a short reaction time of 10–30 minutes and with methanol as the cosolvent, the optimal conditions for Xyl_I against 10-DAXP were 40 °C and pH 7.0–7.5; for the isolated subunit Xyl_S, these conditions were 30 °C and pH 7.5 (Fig. 2). Moreover, among the nine metal ions tested, only calcium showed an activation effect for the β-xylosidase activity of Xyl_I against 10-DAXP, and the maximum activity of 127% was achieved at a final Ca2+ concentration of 10 mM compared with the blank control (Fig. 2c). For the isolated subunit Xyl_S, however, none of the metal ions tested had activation effects on its activity against 10-DAXP (Fig. 2b). A response surface analysis using the reaction rate as the response was carried out by central composite design, taken into account the reaction temperature and the proportion of saturated methanolic solutions of 10-DAXP (8.3 mg/ml, or 8.5 mM). The results showed that, for Xyl_I, the apparent maximum reaction rate of 0.030 μmol/min/mg could be achieved at 30 °C in 25% 10-DAXP solution. For Xyl_S, this rate was 0.026 μmol/min/mg at 30 °C in 23% 10-DAXP solution (Fig. 2d,e).


Functional and structural properties of a novel cellulosome-like multienzyme complex: efficient glycoside hydrolysis of water-insoluble 7-xylosyl-10-deacetylpaclitaxel.

Dou TY, Luan HW, Ge GB, Dong MM, Zou HF, He YQ, Cui P, Wang JY, Hao DC, Yang SL, Yang L - Sci Rep (2015)

Optimum conditions for the hydrolysis of the C-7 xylosidic bond of DAXP.(a) Effect of pH, (b) metal ions and (c) the concentration of calcium on the 10-DAXP xylosidase activity of the purified multienzyme complex Xyl_I, and the key catalytic subunit Xyl_S isolated from it. (d) Xyl_I, and (e) Xyl_S, response surface analysis concerning the effect of reaction temperature and proportion of saturated methanol solutions on the desired activity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562250&req=5

f2: Optimum conditions for the hydrolysis of the C-7 xylosidic bond of DAXP.(a) Effect of pH, (b) metal ions and (c) the concentration of calcium on the 10-DAXP xylosidase activity of the purified multienzyme complex Xyl_I, and the key catalytic subunit Xyl_S isolated from it. (d) Xyl_I, and (e) Xyl_S, response surface analysis concerning the effect of reaction temperature and proportion of saturated methanol solutions on the desired activity.
Mentions: To determine the optimal conditions for the hydrolysis of 10-DAXP to 10-DAP, single factors such as temperature, pH, cosolvents, and metal ions were initially investigated. The results showed that DMSO, DMF, and methanol were possible cosolvents for the above hydrolysis reaction. Considering the effects on enzyme activities, methanol was preffered for this reaction (Supplementary Table 2), particularly for the kinetic analysis of the purified enzymes against 10-DAXP. Within a short reaction time of 10–30 minutes and with methanol as the cosolvent, the optimal conditions for Xyl_I against 10-DAXP were 40 °C and pH 7.0–7.5; for the isolated subunit Xyl_S, these conditions were 30 °C and pH 7.5 (Fig. 2). Moreover, among the nine metal ions tested, only calcium showed an activation effect for the β-xylosidase activity of Xyl_I against 10-DAXP, and the maximum activity of 127% was achieved at a final Ca2+ concentration of 10 mM compared with the blank control (Fig. 2c). For the isolated subunit Xyl_S, however, none of the metal ions tested had activation effects on its activity against 10-DAXP (Fig. 2b). A response surface analysis using the reaction rate as the response was carried out by central composite design, taken into account the reaction temperature and the proportion of saturated methanolic solutions of 10-DAXP (8.3 mg/ml, or 8.5 mM). The results showed that, for Xyl_I, the apparent maximum reaction rate of 0.030 μmol/min/mg could be achieved at 30 °C in 25% 10-DAXP solution. For Xyl_S, this rate was 0.026 μmol/min/mg at 30 °C in 23% 10-DAXP solution (Fig. 2d,e).

Bottom Line: This cellulosome-like multienzyme complex has a novel structure distinct from the well-documented ones.The key catalytic subunit responsible for the β-xylosidase activity against 10-DAXP is identified to be a novel protein, indicating a new glycoside hydrolase (GH) family.The pioneering work described here offers a novel nanoscale biocatalyst for the production of biofuels and chemicals from renewable plant-based natural resources.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.

ABSTRACT
Cellulosome is a kind of multienzyme complex that displays high activity, selectivity, and stability. Here, we report a novel, non-cellulolytic, cellulosome-like multienzyme complex that produced by the Cellulosimicrobium cellulans wild-type strain F16 isolated from soil microflora. This multienzyme complex, with excellent catalytic efficiency of kcat 13.2 s(-1) to remove the C-7 xylosyl group from 7-xylosyl-10-deacetylpaclitaxel (10-DAXP), has an outstanding tolerance against organic solvents and an excellent general stability, with the long half-life of 214 hours. This cellulosome-like multienzyme complex has a novel structure distinct from the well-documented ones. The key catalytic subunit responsible for the β-xylosidase activity against 10-DAXP is identified to be a novel protein, indicating a new glycoside hydrolase (GH) family. The pioneering work described here offers a novel nanoscale biocatalyst for the production of biofuels and chemicals from renewable plant-based natural resources.

No MeSH data available.


Related in: MedlinePlus