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Combining the physical adsorption approach and the covalent attachment method to prepare a bifunctional bioreactor.

Dong M, Wu Z, Lu M, Wang Z, Li Z - Int J Mol Sci (2012)

Bottom Line: The property of amino-functionalized mesoporous silica was characterized by N(2) adsorption-desorption and thermogravimetric (TG) analysis.With Micrococus lysodeilicus as the substrate, the antibacterial activity of covalently tethered lysozyme was measured.Results demonstrated that the final product not only presented peroxidase activity of the myoglobin but yielded antibacterial activity of the lysozyme.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China; E-Mails: dong.meng.xing@163.com (M.D.); wuzf06@mails.jlu.edu.cn (Z.W.); luming@jlu.edu.cn (M.L.); wangzhi@jlu.edu.cn (Z.W.).

ABSTRACT
Aminopropyl-functionalized SBA-15 mesoporous silica was used as a support to adsorb myoglobin. Then, in order to avoid the leakage of adsorbed myoglobin, lysozyme was covalently tethered to the internal and external surface of the mesoporous silica with glutaraldehyde as the coupling agent. The property of amino-functionalized mesoporous silica was characterized by N(2) adsorption-desorption and thermogravimetric (TG) analysis. The feature of the silica-based matrix before and after myoglobin adsorption was identified by fourier transform infrared (FTIR) and UV/VIS measurement. With o-dianisidine and H(2)O(2) as the substrate, the peroxidase activity of adsorbed myoglobin was determined. With Micrococus lysodeilicus as the substrate, the antibacterial activity of covalently tethered lysozyme was measured. Results demonstrated that the final product not only presented peroxidase activity of the myoglobin but yielded antibacterial activity of the lysozyme.

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(a) Nitrogen adsorption-desorption isotherms and (b) BJH (Barrett-Joyner-Halenda) pore size distribution plots of amino-functionalized mesoporous silica synthesized using the co-condensation method.
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f2-ijms-13-11443: (a) Nitrogen adsorption-desorption isotherms and (b) BJH (Barrett-Joyner-Halenda) pore size distribution plots of amino-functionalized mesoporous silica synthesized using the co-condensation method.

Mentions: As suggested by Soofin et al., the mesoporous ordering of amine-silane decreased with the increasing molar composition of APTES in the synthesis system [17]. When the molar composition was close to 0.2, X-ray diffraction peaks of amine-silane began to weaken. In order to simultaneously acquire the maximum loading of amino group and ordered mesostructure, 0.2 was chosen as the molar composition of the APTES in this experiment. The sample showed the H1 type hysteresis loop (Figure 2a). The pore size distribution of the sample was very sharp (Figure 2b). The BET surface area, pore volume and BJH pore diameter were 250 m2/g, 0.41 cm3/g and 5.7 nm, respectively. It is necessary that the pore size should be larger than the molecular size of the enzyme to ensure successful adsorption [18]. Furthermore, when the size of the mesoporous material matches the dimension of the enzyme molecule, the enzyme is deeply absorbed into the internal surface of mesoporous material rather than on the external surface [7,19]. Myoglobin (Mr 16700) contains a single polypeptide of 153 amino acid residues with one molecule of heme as a prosthetic group. The myoglobin possesses a molecular dimension of 4.5 nm × 3.5 nm × 2.5 nm [20]. Obviously, amino-functionalized mesoporous silica synthesized in this experiment was suitable for the adsorption of myoglobin.


Combining the physical adsorption approach and the covalent attachment method to prepare a bifunctional bioreactor.

Dong M, Wu Z, Lu M, Wang Z, Li Z - Int J Mol Sci (2012)

(a) Nitrogen adsorption-desorption isotherms and (b) BJH (Barrett-Joyner-Halenda) pore size distribution plots of amino-functionalized mesoporous silica synthesized using the co-condensation method.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472756&req=5

f2-ijms-13-11443: (a) Nitrogen adsorption-desorption isotherms and (b) BJH (Barrett-Joyner-Halenda) pore size distribution plots of amino-functionalized mesoporous silica synthesized using the co-condensation method.
Mentions: As suggested by Soofin et al., the mesoporous ordering of amine-silane decreased with the increasing molar composition of APTES in the synthesis system [17]. When the molar composition was close to 0.2, X-ray diffraction peaks of amine-silane began to weaken. In order to simultaneously acquire the maximum loading of amino group and ordered mesostructure, 0.2 was chosen as the molar composition of the APTES in this experiment. The sample showed the H1 type hysteresis loop (Figure 2a). The pore size distribution of the sample was very sharp (Figure 2b). The BET surface area, pore volume and BJH pore diameter were 250 m2/g, 0.41 cm3/g and 5.7 nm, respectively. It is necessary that the pore size should be larger than the molecular size of the enzyme to ensure successful adsorption [18]. Furthermore, when the size of the mesoporous material matches the dimension of the enzyme molecule, the enzyme is deeply absorbed into the internal surface of mesoporous material rather than on the external surface [7,19]. Myoglobin (Mr 16700) contains a single polypeptide of 153 amino acid residues with one molecule of heme as a prosthetic group. The myoglobin possesses a molecular dimension of 4.5 nm × 3.5 nm × 2.5 nm [20]. Obviously, amino-functionalized mesoporous silica synthesized in this experiment was suitable for the adsorption of myoglobin.

Bottom Line: The property of amino-functionalized mesoporous silica was characterized by N(2) adsorption-desorption and thermogravimetric (TG) analysis.With Micrococus lysodeilicus as the substrate, the antibacterial activity of covalently tethered lysozyme was measured.Results demonstrated that the final product not only presented peroxidase activity of the myoglobin but yielded antibacterial activity of the lysozyme.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, College of Life Sciences, Jilin University, Changchun 130012, China; E-Mails: dong.meng.xing@163.com (M.D.); wuzf06@mails.jlu.edu.cn (Z.W.); luming@jlu.edu.cn (M.L.); wangzhi@jlu.edu.cn (Z.W.).

ABSTRACT
Aminopropyl-functionalized SBA-15 mesoporous silica was used as a support to adsorb myoglobin. Then, in order to avoid the leakage of adsorbed myoglobin, lysozyme was covalently tethered to the internal and external surface of the mesoporous silica with glutaraldehyde as the coupling agent. The property of amino-functionalized mesoporous silica was characterized by N(2) adsorption-desorption and thermogravimetric (TG) analysis. The feature of the silica-based matrix before and after myoglobin adsorption was identified by fourier transform infrared (FTIR) and UV/VIS measurement. With o-dianisidine and H(2)O(2) as the substrate, the peroxidase activity of adsorbed myoglobin was determined. With Micrococus lysodeilicus as the substrate, the antibacterial activity of covalently tethered lysozyme was measured. Results demonstrated that the final product not only presented peroxidase activity of the myoglobin but yielded antibacterial activity of the lysozyme.

Show MeSH
Related in: MedlinePlus