Literature summary for 3.2.1.1 extracted from

Uma Maheswar Rao, J.L.; Satyanarayana, T.
Biophysical and biochemical characterization of a hyperthermostable and Ca2+ -independent alpha-amylase of an extreme thermophile Geobacillus thermoleovorans (2008), Appl. Biochem. Biotechnol., 150, 205-219.

Crystallization (Commentary)

Crystallization (Comment)	Organism
the circular dichroism spectrocopic data reveal the native alpha-amylase gt to contain 25% alpha-helix, 21% beta-sheet, and 54% random coils at pH 8.0. The fluorescence intensity increases with a shift in pH from neutral to acidic range while it decreases with increasing pH. With the pH change from neutral to basic, there is no significant change in the alpha-helix content. As the temperature increases from 40 to 110°C, no change in the alpha-helix content is observed, which remains around 22% at all temperatures	Geobacillus thermoleovorans

Crystallization (Comment)

Organism

the circular dichroism spectrocopic data reveal the native alpha-amylase gt to contain 25% alpha-helix, 21% beta-sheet, and 54% random coils at pH 8.0. The fluorescence intensity increases with a shift in pH from neutral to acidic range while it decreases with increasing pH. With the pH change from neutral to basic, there is no significant change in the alpha-helix content. As the temperature increases from 40 to 110°C, no change in the alpha-helix content is observed, which remains around 22% at all temperatures

Geobacillus thermoleovorans

Inhibitors

Inhibitors	Comment	Organism
guanidine hydrochloride	0.05 to 0.6 mM, as the concentraion is increased, the loss of of the whole conformational structure occurs and the relative activity decreases from 80% at 0.05 mM to 29% at 0.6 mM compared to the control, pH 8.0, 100°C	Geobacillus thermoleovorans
KI	0.05 to 0.6 mM, with 88% relative enzyme activity at 0.05 M decreasing to 42% at 0.6 mM compared to the control, also loss of fluorescence intensity, pH 8.0, 100°C	Geobacillus thermoleovorans
N-bromosuccinimide	in the presence of 14 mM N-bromosuccinimide alpha-helix content and alpha-amlyase gt activity decrease with no observable change in beta-sheets, pH 8.0, 100°C	Geobacillus thermoleovorans
Urea	0.6 M, 50% decrease of enzyme activity compared to control, the circular dichroism spectra in the presence of urea reveals the unfolding of the enzyme which leads to changes in both alpha-helices as well as beta-sheets content. These conformational chages could be responsible for the decline in the alpha-amylase activity	Geobacillus thermoleovorans

Metals/Ions

Metals/Ions	Comment	Organism	Structure
additional information	does not require Ca2+ for its stability or activity	Geobacillus thermoleovorans
additional information	no quantitative change in the activity even at high concentrations of acrylamide, 0.05 to 0.6 mM. The addition of CsCl decreases the fluorescence quenching with no influence on enzyme activity	Geobacillus thermoleovorans

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
26000	-	non-denaturing PAGE	Geobacillus thermoleovorans

Organism

Organism	UniProt	Comment	Textmining
Geobacillus thermoleovorans	-	-	-

Purification (Commentary)

Purification (Comment)	Organism
-	Geobacillus thermoleovorans

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
starch + H2O	soluble starch as substrate	Geobacillus thermoleovorans	?	the liberated reducing sugars are determined using dinitrosalicylic acid reagent	?

Synonyms

Synonyms	Comment	Organism
alpha-amylase gt	-	Geobacillus thermoleovorans
Ca2+-independent alpha-amylase gt	-	Geobacillus thermoleovorans

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
100	-	optimum and assay at	Geobacillus thermoleovorans

Temperature Range [°C]

Temperature Minimum [°C]	Temperature Maximum [°C]	Comment	Organism
40	110	20% relative activity at 40°C, 90% relative activity at 110°C. As the temperature increases, no change in the alpha-helix content is observed, which remains around 22% at all temperatures	Geobacillus thermoleovorans

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
8	-	optimum and assay at	Geobacillus thermoleovorans

pH Range

pH Minimum	pH Maximum	Comment	Organism
4	9	40% relative activity at pH 4, above 90% relative activity at pH 9.0. The fluorescence intensity increases with a shift in pH from neutral to acidic range while it decreases with increasing pH. With the pH change from neutral to basic, there is no significant change in the alpha-helix content. This is in accordance with the enzyme activity that changes marginally. The enzyme activity decreases with the lowering of pH, and the highest activity is recorded at pH 8.0. Only a slight decline in activity is seen with further increase in pH	Geobacillus thermoleovorans