The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform

Suren Singh - One of the best experts on this subject based on the ideXlab platform.

  • purification and biochemical characteristics of β d glucosidase from a thermophilic fungus thermomyces lanuginosus ssbp
    Biotechnology and Applied Biochemistry, 1999
    Co-Authors: Balakrishna Pillay, Suren Singh
    Abstract:

    : An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

  • Purification and biochemical characteristics of beta-D-xylanase from a thermophilic fungus, Thermomyces lanuginosus-SSBP.
    Biotechnology and applied biochemistry, 1999
    Co-Authors: J Lin, Suren Singh, L M Ndlovu, Balakrishna Pillay
    Abstract:

    An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

  • Purification and biochemical characteristics of β‐D‐glucosidase from a thermophilic fungus, Thermomyces lanuginosus–SSBP
    Biotechnology and applied biochemistry, 1999
    Co-Authors: J Lin, Balakrishna Pillay, Suren Singh
    Abstract:

    An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

Ki-hong Yoon - One of the best experts on this subject based on the ideXlab platform.

  • characterization of a paenibacillus woosongensis beta xylosidase Alpha Arabinofuranosidase produced by recombinant escherichia coli
    Journal of Microbiology and Biotechnology, 2010
    Co-Authors: Yeon A. Kim, Ki-hong Yoon
    Abstract:

    A gene encoding the beta-xylosidase/Alpha-Arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium beta-xylosidase/Alpha-N-arabinosidase and Bacillus cellulosilyticus Alpha-Arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a Cterminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on paranitrophenyl- Alpha-arabinofuranoside (pNPA) as well as paranitrophenyl- beta-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

  • Characterization of a Paenibacillus woosongensis beta-Xylosidase/Alpha-Arabinofuranosidase produced by recombinant Escherichia coli.
    Journal of microbiology and biotechnology, 2010
    Co-Authors: Yeon A. Kim, Ki-hong Yoon
    Abstract:

    A gene encoding the beta-xylosidase/Alpha-Arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium beta-xylosidase/Alpha-N-arabinosidase and Bacillus cellulosilyticus Alpha-Arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a Cterminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on paranitrophenyl- Alpha-arabinofuranoside (pNPA) as well as paranitrophenyl- beta-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

Balakrishna Pillay - One of the best experts on this subject based on the ideXlab platform.

  • purification and biochemical characteristics of β d glucosidase from a thermophilic fungus thermomyces lanuginosus ssbp
    Biotechnology and Applied Biochemistry, 1999
    Co-Authors: Balakrishna Pillay, Suren Singh
    Abstract:

    : An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

  • Purification and biochemical characteristics of beta-D-xylanase from a thermophilic fungus, Thermomyces lanuginosus-SSBP.
    Biotechnology and applied biochemistry, 1999
    Co-Authors: J Lin, Suren Singh, L M Ndlovu, Balakrishna Pillay
    Abstract:

    An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

  • Purification and biochemical characteristics of β‐D‐glucosidase from a thermophilic fungus, Thermomyces lanuginosus–SSBP
    Biotechnology and applied biochemistry, 1999
    Co-Authors: J Lin, Balakrishna Pillay, Suren Singh
    Abstract:

    An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

Yeon A. Kim - One of the best experts on this subject based on the ideXlab platform.

  • characterization of a paenibacillus woosongensis beta xylosidase Alpha Arabinofuranosidase produced by recombinant escherichia coli
    Journal of Microbiology and Biotechnology, 2010
    Co-Authors: Yeon A. Kim, Ki-hong Yoon
    Abstract:

    A gene encoding the beta-xylosidase/Alpha-Arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium beta-xylosidase/Alpha-N-arabinosidase and Bacillus cellulosilyticus Alpha-Arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a Cterminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on paranitrophenyl- Alpha-arabinofuranoside (pNPA) as well as paranitrophenyl- beta-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

  • Characterization of a Paenibacillus woosongensis beta-Xylosidase/Alpha-Arabinofuranosidase produced by recombinant Escherichia coli.
    Journal of microbiology and biotechnology, 2010
    Co-Authors: Yeon A. Kim, Ki-hong Yoon
    Abstract:

    A gene encoding the beta-xylosidase/Alpha-Arabinofuranosidase (XylC) of Paenibacillus woosongensis was cloned into Escherichia coli. This xylC gene consisted of 1,425 nucleotides, encoding a polypeptide of 474 amino acid residues. The deduced amino acid sequence exhibited an 80% similarity with those of both Clostridium stercorarium beta-xylosidase/Alpha-N-arabinosidase and Bacillus cellulosilyticus Alpha-Arabinofuranosidase, belonging to the glycosyl hydrolase family 43. The structural gene was subcloned with a Cterminal His-tag into a pET23a(+) expression vector. The His-tagged XylC, purified from a cell-free extract of a recombinant E. coli BL21(DE3) Codon Plus carrying a xylC gene by affinity chromatography, was active on paranitrophenyl- Alpha-arabinofuranoside (pNPA) as well as paranitrophenyl- beta-xylopyranoside (pNPX). However, the enzymatic activities for the substrates were somewhat incongruously influenced by reaction pHs and temperatures. The enzyme was also affected by various chemicals at different levels. SDS (5 mM) inhibited the enzymatic activity for pNPX, while enhancing the enzymatic activity for pNPA. Enzyme activity was also found to be inhibited by addition of pentose or hexose. The Michaelis constant and maximum velocity of the purified enzyme were determined for hydrolysis of pNPX and pNPA, respectively.

J Lin - One of the best experts on this subject based on the ideXlab platform.

  • Purification and biochemical characteristics of beta-D-xylanase from a thermophilic fungus, Thermomyces lanuginosus-SSBP.
    Biotechnology and applied biochemistry, 1999
    Co-Authors: J Lin, Suren Singh, L M Ndlovu, Balakrishna Pillay
    Abstract:

    An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.

  • Purification and biochemical characteristics of β‐D‐glucosidase from a thermophilic fungus, Thermomyces lanuginosus–SSBP
    Biotechnology and applied biochemistry, 1999
    Co-Authors: J Lin, Balakrishna Pillay, Suren Singh
    Abstract:

    An extracellular xylanase was purified to homogeneity from the culture filtrate of a thermophilic fungus, Thermomyces lanuginosus-SSBP, and its biochemical characteristics were studied. A yield of 70-80% was achieved through the procedures of 80%-satd. ammonium sulphate precipitation, DEAE-Sephadex A25 and quaternary aminoethyl (QAE)-Sephadex A25 column chromatography. The molecular mass of the purified xylanase was 23.6 kDa, as analysed by SDS/PAGE, with a pI value of 3.8. The molar absorption coefficient of the absorbance at 280 nm was 6.8x10(4) M(-1).cm(-1). The specific activity, calculated using the dinitrosalicylic acid (DNS) method, was 3500 units/mg. The enzyme reactions followed Michaelis-Menten kinetics with K app m and V(max) values of 3.26 mg/ml and 6300 units/ml per mg of protein respectively, as obtained from a Lineweaver-Burk plot. The xylanase contained no other enzyme activity (cellulase, beta-glucosidase, beta-mannosidase, Alpha-Arabinofuranosidase, or beta-xylosidase) except for the hydrolysis of xylan substrate. The optimal temperature of the enzyme assay was 70-75 degrees C. The enzyme retained full activity after a 60 degrees C incubation for 3 h. The optimal pH of xylanase activity was 6.5 and the enzyme appeared to be stable over a broad pH range (pH 5-12) under the assay conditions. The majority of the metal ions tested had no effect on the enzyme activity, with the exception of Pb(2+) (modest inhibitor) and Hg(2+) (strong inhibitor). The results showed that one or two tryptophan residues oxidized by N-bromosuccinamide per enzyme molecule was sufficient to inhibit the enzyme activity completely, thus indicating that the tryptophan residues play an important role in the catalytical processes of the enzyme reaction. Because of the outstanding properties of the purified xylanase from the SSBP strain, this xylanase has a potential use in biopulping processes and other industrial applications.