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Structural and biochemical properties of a novel pullulanase of Paenibacillus lautus DSM 3035
Author(s) -
Chen SiQi,
Cai XiangHai,
Xie JingLi,
Wei Wei,
Wei DongZhi
Publication year - 2017
Publication title -
starch ‐ stärke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.62
H-Index - 82
eISSN - 1521-379X
pISSN - 0038-9056
DOI - 10.1002/star.201500333
Subject(s) - pullulanase , pullulan , biochemistry , enzyme , recombinant dna , amylopectin , escherichia coli , heterologous expression , chemistry , molecular mass , microbiology and biotechnology , biology , amylose , gene , starch , polysaccharide
The pullulanase gene ( pul PL ), encoding a novel type I pullulanase (Pul PL ), was obtained from a Paenibacillus lautus DSM3035 isolate. The gene has an open reading frame of 2355 bp, After optimizing induction conditions in Escherichia coli , we overexpressed recombinant Pul PL , purified this enzyme, and assayed its function . The level of functional Pul PL ‐like protein reached its maximum (about 0.28 mg/mL, 15% of total protein) after induction for 16 h at 20°C. Under these optimized harvesting conditions, Pul PL activity was 11.1 U/mL. The purified recombinant enzyme with an apparent molecular mass of about 87.9 kDa was able to specifically attack the α‐1,6 linkages in pullulan to generate maltotriose as the major product. The purified Pul PL exhibited optimal activity at pH 7.0 and 40°C. The Pul PL hydrolyzed pullulan, amylopectin, starch, and glycogen, but not amylose. Substrate specificity observations and reaction products identifications indicate that the purified pullulanase from P. lautus DSM3035 is a type I pullulanase. The present report, to our knowledge, the first to identify type I pullulanase in P.lautus , and detail the enzymatic properties of this enzyme after heterologous expression.