Thermostability of three ?-amylases of Streptomyces sp IMD 2679

McMahon, Hilary E.M.; Kelly, Catherine T.; Fogarty, William M.

doi:10.1038/sj.jim.2900612

Cited by 9 publications

(7 citation statements)

References 13 publications

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“…In mammals, these genes code for salivary and pancreatic a-amylases (Robins & Samuelson, 1992). As a consequence of the gene size and multitude of alleles, polymorphism of a-amylases is observed even among individuals belonging to the same species (Nebinger, 1986;Strumeyer et al, 1988;McMahon et al, 1999;Terziè et al, 1999). From two to six isoenzymatic forms dif- The enzymes were preincubated in 1.0 ml of veronal/Na acetate buffer, pH 7.4 or 8.4 for 15 min at 37°C with each of the effectors before the addition of substrate.…”

Section: Discussionmentioning

confidence: 99%

Purification and characterization of alpha-amylases from the intestine and muscle of ascaris suum (Nematoda).

Zoltowska¹

2001

Acta Biochim Pol

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Alpha-Amylase (EC 3.2.1.1) was purified from the muscle and intestine of the parasitic helminth of pigs Ascaris suum. The enzymes from the two sources differed in their properties. Isoelectric focusing revealed one form of a-amylase from muscles with pl of 5.0, and two forms of amylase from intestine with pI of 4.7 and 4.5. SDS/PAGE suggested a molecular mass of 83 kDa and 73 kDa for isoenzymes of a-amylases from intestine and 59 kDa for the muscle enzyme. Alpha-Amylase from intestine showed maximum activity at pH 7.4, and the enzyme from muscle at pH 8.2. The muscle enzyme was more thermostabile than the intestinal alpha-amylase. Both the muscle and intestine amylase lost half of its activity after 15 min at 70 degrees C and 50 degrees C, respectively. The Km values were: for muscle amylase 0.22 microg/ml glycogen and 3.33 microg/ml starch, and for intestine amylase 1.77 microg/ml glycogen and 0.48 microg/ml starch. Both amylases were activated by Ca2+ and inhibited by EDTA, iodoacetic acid, p-chloromercuribenzoate and the inhibitor of a-amylase from wheat. No significant differences were found between the properties of a-amylases from parasites and from their hosts.

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Section: Discussionmentioning

confidence: 99%

Purification and characterization of alpha-amylases from the intestine and muscle of ascaris suum (Nematoda).

Zoltowska¹

2001

Acta Biochim Pol

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“…Thermostable α-amylases have had many commercial applications for several decades. These enzymes are used in the textile and paper industries, food, adhesive, and sugar production (12,15,16,18,21,22).…”

Section: Introductionmentioning

confidence: 99%

Production and properties of alpha-amylase from thermophilic Bacillus sp.

Cordeiro¹,

Martins²,

Luciano³

2002

Braz. J. Microbiol.

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α-amylase (1,4-α-D-glucan glucanohydrolase, EC 3.2.1.1) production by thermophilic Bacillus sp strain SMIA-2 cultivated in liquid media containing soluble starch reached a maximum at 48h, with levels of 57U/ mL. Studies on the α-amylase characterization revealed that the optimum temperature for activity was 70ºC. The enzyme was stable for 2h at 50ºC, while at 60ºC, 70ºC and 90ºC, 4%, 13% and 38% of the original activities were lost, respectively. The optimum pH of the enzyme was 7.5. After incubation of crude enzyme solution for 24h at pH 7.5, a decrease of about 5% of its original activity was observed. The enzyme was strongly inhibited by Co 2+ , Cu 2+ and Ba 2+ , but less affected by Ca 2+ , Mg 2+ , Ni 2+ , Sr 2+ and Mn 2+. The enzyme in 1M and 5M NaCl solutions the enzyme retained 70% and 47% of the original activity after 24h of incubation at 4ºC, respectively.

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“…The starch processing industry requires the use of amylolytic enzymes at high temperatures (Uguru et al, 1997;Bolton et al, 1997). Thermophilic organisms are therefore of special interest as a source of novel thermostable enzymes (Chandra et al, 1980;McMahon et al, 1997;McMahon et al, 1999). The advantages for using thermostable ∝-amylases in industrial processes include the decreased risk of contamination, the increased diffusion rate and the decreased cost of external cooling (Lin et al, 1998).…”

Section: Introductionmentioning

confidence: 99%