TABLE 2.
Molecular interactions of porcine pancreatic alpha-amylase, human pancreatic alpha-amylase, and human salivary alpha-amylase with acarbose and the pregnane compounds (P1–P4) derived from G. latifolium.
| Enzymes | Active site docking | Blind docking | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Compounds | Hydrogen bond interactions | Hydrophobic interaction | Hydrogen bond interaction | Hydrophobic interaction | |||||
| No | Residues | No | Residues | No | Residues | No | Residues | ||
| Acarbose | PPA | 4 | Asp300 (3) and Gly306 | 3 | Lys200, Ile235, and Tyr151 | 3 | Arg252, Lys278, and Glu404 | 1 | Pro332 |
| P1 | 3 | His 299 and Asp 300 (2) | 10 | Leu162 (2), Ala198, Ile235, Leu165, Trp58, Tyr62 (3), and His201 | 6 | His 299, Gly306, Asp300(2), and Glu233 (2) | 8 | Leu162 (2), Ala198, Leu165, Trp58, Tyr62 (2), and His201 | |
| P2 | 1 | His299 | 7 | Val163(2), Leu162 (2), Lys200, His201, and His299 | 6 | Arg252, Trp280, Gly334, His331, Asn279, and Trp280 | 4 | Pro332 (2), Pro405, and Phe335 | |
| P3 | 1 | His299 | 4 | Leu162, Ile235, and Tyr62 | 8 | Arg252, Ser289, Pro332, Gly334, His331 (2), Asn279, and Trp280 | 3 | Pro4 and Phe335 (2) | |
| P4 | 5 | Asp300 (3) and Glu240 (2) | 9 | Leu162 (2), Ala198, Ile235, Ala307, Trp58, Tyr62 (2), and His201 | 5 | Lys200, Glu240, Glu233 (2), and Asp300 | 8 | Leu162 (2), Ala198, Ile235, Ala307, Leu237, Tyr62, and His201 | |
| Acarbose | HPA | 8 | Lys200, His305 (2), Asp300 (3), and Glu233 (2) | 2 | Trp58 and Trp59 | 6 | Glu233 (3), Asp300, His305, and Gly306 | 2 | Trp58 and Trp59 |
| P1 | 3 | Glu233 (2) and Asp300 | 8 | Leu162 (2), Leu165 (2), Ala198, Ile235, Leu162, and His201 | 4 | Asp197, Glu233, Ala198, and Gln63 | 10 | Leu162 (3), Leu165 (2), Ala198, Ile235, Trp59, His201, and Gln63 | |
| P2 | 3 | Asp197, Thr163, and Tyr151 | 10 | Tyr151 (3), Ile235 (2), Trp58 (2), Trp59, His299, and His305 | 4 | Asp300, Thr163, and Glu240 | 9 | Tyr151, Trp59 (4), Leu162, Tyr62, His201, and His305 | |
| P3 | 3 | Thr163 and Asp300 (2) | 11 | Leu162, (2), Ile235 (2), Trp58, Trp59 (2), Tyr62, Tyr151, and His201 | 3 | Thr163, Glu240, and Gly239 | 15 | Leu162 (2), Ala198, Ile235 (2), Trp58, Ala307, Leu237 (2), Tyr62 (2), and His201 (2) | |
| P4 | 6 | Glu233, Glu240 (2), Asp300 His305, and Gly306 | 10 | Leu162 (2), Ala198, Ile235, Trp58, Tyr62 (2), Tyr151 (2), and His201 | 5 | Thr163, Asp300 (2), His305, and Gly306 | 6 | Leu162, Ile235, Leu162, Leu237, Tyr62, and Tyr151 | |
| Acarbose | HSA | 3 | Asp300, Gly306, and Lys200 | 3 | Trp58, Trp59, and His305 | 5 | Asp300 (2), Arg195, and Lys352 (2) | 1 | Trp59 |
| P1 | 2 | Glu233 and Asp300 | 7 | Leu162 (2), Ala198, Leu165, Tyr62, and His201 (2) | 3 | Asp300 (3) | 10 | Leu162 (2), Leu165, Ala198, Trp58, Tyr62 (2), His101, and His201 | |
| P2 | 3 | Glu233 and Asp300 (2) | 9 | Trp59 (2), Leu162 (2), Ala198, Ala307, Tyr62, and His201 (2) | 5 | Asp300, Ser163, His305, and Leu237 | 7 | Tyr151, Trp59 (3), Leu162 (2), and His305 | |
| P3 | 3 | Asp300 (2) and Glu240 | 12 | Leu162 (2), Ala198, Ala307, Ile235, Leu237, Trp58, Tyr62 (2), His101, and His201 (2) | 5 | Glu233, Asp300 (2), Glu240, and Lys200 | 11 | Leu162 (2), Ala198, Ala307, Ile235, Trp58, Tyr62 (2), His101, and His201 (2) | |
| P4 | 4 | Asp300 (3) and Glu240 | 10 | Leu162 (2), Ala198, Ile235 (2), Trp68, Tyr62 (2), His101, and His201 | 3 | Asp300 (2) and Glu240 | 10 | Leu162 (2), Ala198, Ile235 (2), Trp58, Tyr62 (2), His101, and His 201 | |
NB: P1, marsectohexol; P2, 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→14)-β-D-oleandropyranosyl]-11,12-di-O-tigloyl-17β-marsdenin; P3, 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-oleandropyranosyl]-17β-marsdenin; P4, 3-O-[6-deoxy-3-O-methyl-β-D-allopyranosyl-(1→4)-β-D-canaropyranosyl]-17β-marsdenin. Amino acid residues in bold font are members of the catalytic triad. Figures in parenthesis indicate multiple bonds exhibited by the residues. Amino acids in bold fonts are the catalytic residues.