Palupi, I.F.J.; Putri, K.D.A.; Purwani, N.N.; Sumarsih, S.; Puspaningsih, N.N.T. Kinetic Characterization of β-xylosidase (GbtXyl43A) from Wild-type Geobacillus thermoleovorans IT-08 and The Variant GbtXyl43A-D121N. Preprints2020, 2020090585. https://doi.org/10.20944/preprints202009.0585.v1
APA Style
Palupi, I.F.J., Putri, K.D.A., Purwani, N.N., Sumarsih, S., & Puspaningsih, N.N.T. (2020). Kinetic Characterization of β-xylosidase (GbtXyl43A) from Wild-type Geobacillus thermoleovorans IT-08 and The Variant GbtXyl43A-D121N. Preprints. https://doi.org/10.20944/preprints202009.0585.v1
Chicago/Turabian Style
Palupi, I.F.J., Sri Sumarsih and Ni Nyoman Tri Puspaningsih. 2020 "Kinetic Characterization of β-xylosidase (GbtXyl43A) from Wild-type Geobacillus thermoleovorans IT-08 and The Variant GbtXyl43A-D121N" Preprints. https://doi.org/10.20944/preprints202009.0585.v1
Abstract
GbtXyl43A, a β-xylosidase that is isolated from Geobacillus thermoleovorans IT-08 and grouped in GH43 family. The substitution of 121Asp residue with Asn in GbtXyl43A caused decrease the enzyme activity. The aim of this study, determine the kinetic characteristics of wild-type GbtXyl43A and D121N variant using Vmax, KM, kcat, and kcat/KM. These parameters indicated catalytic mechanism of GbtXyl43A and its derivative. All of them were produced in Escherichia coli BL21 star. The purification of wild-type GbtXyl43A using affinity chromatography, but D121N variant also required anion-exchange chromatography. The specific activity of wild-type GbtXyl43A and D121N variant were 0.471 U mg-1 in purity level 55,44 and 0.012 U mg-1 in purity level 2,407, respectively. Both enzymes had same molecular weight, ~58 kDa. The kinetic parameters of wild-type GbtXyl43A were KM: 2.845 mM, kcat: 0.033 s-1, Vmax: 0.0033 mM min-1and kcat/KM: 0.0115 s-1mM-1. Furthermore, the KM, kcat, Vmax, and kcat/KM values of D121N variant were 4.565 mM, 1.01 × 10-4 mM min-1, 0.140 × 10-4 s-1, and 0.0307 s-1mM-1, respectively. The KM value of the D121N variant was higher than its wild type and showed the affinity of D121N variant was lower than GbtXyl43A
Biology and Life Sciences, Biochemistry and Molecular Biology
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