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J. R. Whitaker, “Determination of Molecular Weights of Proteins by Gel Filtration on Sephadex,” Analytical Chemistry, Vol. 35, No. 12, 1963, pp. 1950-1953.

has been cited by the following article:

• TITLE: Purification and Characterization of Alkaline Xylanase Secreted from Paenibacillus macquariensis

  AUTHORS: Meeta Sharma, Saurabh Mehta, Anil Kumar

  KEYWORDS: Xylanase; Paenibacillus macquariensis; Purification; Michaelis Constant; Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis

  JOURNAL NAME: Advances in Microbiology, Vol.3 No.1, March 27, 2013

  ABSTRACT: An alkaline xylanase secreted by Paenibacillus macquariensis RC 1819 has been purified using ammonium sulfate fractionation, ion exchange chromatography using DEAE-cellulose and gel filtration chromatography over Sephadex G-200 and Sephadex G-100. The purified enzyme had the specific activity, 25.2 units/mg protein with birchwood xylan as a substrate. The purified enzyme showed a single protein band over sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight of the enzyme has been found to be 31,000 ± 2000 as determined by using Sephadex G-200 gel filtration chromatography. The subunit molecular weight has also been found to be ~31,000 as determined using SDS-PAGE indicating monomeric enzyme. The enzyme showed optimum activity at pH 8.6 and temperature, 50°C. The Michaelis constant (Km) of the enzyme for birchwood xylan was 2.2 mg/ml as determined using velocity saturation plot. The metal ions viz. Co+2 and Mn+2 stimulated xylanase enzyme activity whereas Hg+2 inhibited the enzyme activity.