Pcal_0768, a hyperactive 4-α-glucanotransferase from Pyrobacculum calidifontis.
Genome sequence of hyperthermophilic archaeon Pyrobaculum calidifontis revealed the presence of an open reading frame, Pcal_0768, corresponding to a putative 4-α-glucanotranferase belonging to glycoside hydrolases (GH) family 77. We have produced, in Escherichia coli, and purified recombinant Pcal_0768 which exhibited high disproportionation (690 U mg(-1)) activity. To the best of our knowledge, this is the highest ever reported activity for any member of family GH77. Maltooligosaccharides, when used as sole substrates, were disproportionated into linear maltooligohomologues. The analysis of the reaction end products revealed no evidence for the production of cycloamyloses. Catalytic activity of the enzyme remained unchanged in the presence or the absence of ionic and nonionic detergents. γ-cyclodextrin, an inhibitor of 4-α-glucanotransferases, did not show any inhibitory effect on Pcal_0768 activity. These properties make Pcal_0768 a potential candidate for starch processing industry.
School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan.
Sumaira
S
Mehboob
Institute of Agricultural Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan.
Nasir
N
Ahmad
School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan. naeemrashid37@hotmail.com.
Naeem
N
Rashid
The Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.
Tadayuki
T
Imanaka
School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan.|School of Biological Sciences, University of Southampton, Southampton, SO16 7PX, UK.
Muhammad
M
Akhtar
D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability / Q000187:drug effects; D006004:Glycogen Debranching Enzyme System / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007218:Industrial Microbiology; D008320:Maltose / Q000378:metabolism; D041543:Pyrobaculum / Q000201:enzymology* / Q000235:genetics; D013213:Starch / Q000378:metabolism; D047408:gamma-Cyclodextrins / Q000494:pharmacology
D019843:Archaeal Proteins; D006004:Glycogen Debranching Enzyme System; D047408:gamma-Cyclodextrins; D008320:Maltose; D013213:Starch; C020569:4 alpha-glucanotransferase
4-α-Glucanotransferase; Disproportionation; Hyperthermophile; Pyrobaculum calidifontis; Transglycosylation