The contact maps of AmyA and AmyB.

<p>The black dots show the common contacts, the pink dots show the contacts which are unique to the native structure and the green for the contacts unique to the truncated enzyme structure.</p

The recapitulation of kinetic constants and general physico-chemical parameters of the AmyA and AmyB of <i>Aspergillus oryzae</i> S2 isoforms.

<p>Kinetic constants were previously evaluated [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153868#pone.0153868.ref023" target="_blank">23</a>]. Physico-chemical parameters revelation was performed using the Swiss-ProtParam tool (<a href="http://www.expasy.org/tools/" target="_blank">http://www.expasy.org/tools/</a>).The instability index computed classified AmyA and AmyB as stable proteins.</p

The Amino-Acid Sequence Analysis of <i>Aspergillus Oryzae</i> S2 α-amylases.

<p>(A, B) The Structure-based multiple sequence alignment of AmyA, AmyB₁, AmyB, AmyB₂, (Accession code Hx2000049571) of <i>Aspergillus oryzae</i> S2 with α-amylase of <i>Aspergillus niger</i> (Accession code 2GUY_A). The invariable residues among sequences are typed in white on a red background; differences between conserved groups are displayed on a yellow background; the numbers (1, 2, 3, and 4) correspond to the disulfide bonds.</p

The zymogram of α-amylase activities.

<p>(A) The zymogram (10%) of α-amylase activities produced in the culture medium from the crude extract of flask incubation containing individually protease inhibitors Leupeptine, PMSF, pepstatine A as well as TPCK (N α-p-Tosyl L- PhenylalanylChloromethyl Ketone). The α-amylases produced in the culture medium from crude extracts without antiproteases were taken as control. (B) The zymogram (20%) of α-amylase activities of 48h and 92h of incubation time.</p

Effect of <i>Agave americana</i> L. on the human, and <i>Aspergillus oryzae</i> S2 α-amylase inhibitions

<p>Among phenolic compounds, <i>Agave americana</i> L. extract contained puerarin (38.4%) and <i>p</i>-coumaric acid (12.29%) (pCa). From the Lineweaver–Burk plots, pCa and puerarin demonstrated a competitive and a non competitive inhibitions towards human α-amylase activity, respectively. PCa exhibited a higher human inhibitory activity with an IC₅₀ of 98.8 μM which was about 2.3 times than acarbose. Puerarin (IC₅₀ = 3.87 μM) and pCa (IC₅₀ = 10.16 μM) also showed an excellent inhibition for <i>Aspergillus oryzae</i> S2 α-amylase activity. The inhibitions of the described biocatalysts compounds towards both amylases were significantly decreased when they were pre-incubated with starch. The binding modes of these compounds were evaluated <i>in silico</i>. The binding efficiency order of these molecules in terms of polar contact numbers for both enzymes was in agreement with the <i>in vitro</i> studies<i>.</i> These findings provided a rational reason to establish the isolated compounds capability as therapeutic target for hyperglycaemia modulation and antifungal therapy.</p