Oxidative Stress Amelioration of Novel Peptides Extracted from Enzymatic Hydrolysates of Chinese Pecan Cake.
Jiaojiao ZhangShaozhen WuQingqing WangQinjie YuanYane LiPatricia Reboredo-RodríguezAlfonso Varela-LópezZhiping HeFenghua WuHao HuXingquan LiuPublished in: International journal of molecular sciences (2022)
Pecan ( Carya cathayensis ) is an important economic crop, and its hydrolyzed peptides have been evidenced to reduce the effect of oxidative stress due to their antioxidant capacity. Hence, the protocols of ultrafiltration and gel filtration chromatography were established to obtain bioactive peptides from by-products of C. cathayensis (pecan cake). As measured by DPPH/ABTS radical scavenging, the peptides with less molecular weight (MW) possess higher antioxidant capacity. PCPH-III (MW < 3 kDa) presented higher radical scavenging capacity than PCPH-II (3 kDa < MW < 10 kDa) and PCPH-I (MW > 10 kDa) measured by DPPH (IC 50 : 111.0 μg/ mL) and measured by ABTs (IC 50 : 402.9 μg/mL). The secondary structure and amino acid composition varied by their MW, in which PCPH-II contained more α-helices (26.71%) and β-sheets (36.96%), PCPH-III contained higher ratios of β-turns (36.87%), while the composition of different secondary of PCPH-I was even 25 ± 5.76%. The variation trend of α-helix and random experienced slightly varied from PCPH-I to PCPH-II, while significantly decreased from PCPH-II to PCPH-III. The increasing antioxidant capacity is followed by the content of proline, and PCPH-III had the highest composition (8.03%). With regard to the six peptides identified by LC-MS/MS, two of them (VYGYADK and VLFSNY) showed stronger antioxidant capacity than others. In silico molecular docking demonstrated their combining abilities with a transcription factor Kelch-like ECH-associated protein 1 (Keap1) and speculated that they inhibit oxidative stress through activating the Keap1-Nrf2-ARE pathway. Meanwhile, increased activity of SOD and CAT-antioxidant markers-were found in H 2 O 2 -induced cells. The residue of tyrosine was demonstrated to contribute the most antioxidant capacity of VYGYADK and its position affected less. This study provided a novel peptide screening and by-product utilization process that can be applied in natural product developments.
Keyphrases
- oxidative stress
- amino acid
- molecular docking
- induced apoptosis
- diabetic rats
- heat shock protein
- transcription factor
- dna damage
- ischemia reperfusion injury
- signaling pathway
- mass spectrometry
- nitric oxide
- endoplasmic reticulum stress
- dna binding
- climate change
- high resolution
- cell death
- cell cycle arrest
- high speed
- cell proliferation
- high performance liquid chromatography
- protein protein
- amyotrophic lateral sclerosis