Kluyveromyces marxianus protein hydrolysates were prepared by two different sonicatedenzymatic (trypsin and chymotrypsin) hydrolysis treatments to obtain antioxidant and
ACE-inhibitory peptides. Trypsin and chymotrypsin hydrolysates obtained by 5 h, exhibited the highest antioxidant and ACE-inhibitory activities. After fractionation using ultrafiltration and reverse phase high performance liquid chromatography (RP-HPLC)
techniques, two new peptides were identified. One fragment (LL-9, MW ¼ 1180 Da) with the
amino acid sequence of Leu-Pro-Glu-Ser-Val-His-Leu-Asp-Lys showed significant ACE
inhibitory activity (IC50 ¼ 22.88 mM) while another peptide fragment (VL-9, MW ¼ 1118 Da)
with the amino acid sequence of Val-Leu-Ser-Thr-Ser-Phe-Pro-Pro-Lys showed the highest
antioxidant and ACE inhibitory properties (IC50 ¼ 15.20 mM, 5568 mM TE/mg protein). The
molecular docking studies revealed that the ACE inhibitory activities of VL-9 is due to
interaction with the S2 (His513, His353, Glu281) and S0
1 (Glu162) pockets of ACE and LL-9
can fit perfectly into the S1 (Thr345) and S2 (Tyr520, Lys511, Gln281) pockets of ACE
کلید واژگان :
K. marxianus Bioactive peptides Antioxidant ACE inhibitory Protein hydrolysate
