Isolation and Characterization of Angiotensin Converting Enzyme Inhibitory Peptides from Green Resources

Abstract

Angiotensin Converting Enzyme (ACE) plays a key role in blood pressure management. The inhibition of ACE is a main target in the regulation of hypertension. In this study, the inhibition potential of bioactive peptides derived from plants against ACE was investigated. Out of twenty plants, Brassica napus, Lens culnaris,Gossypium hirsutum,Arachis hypogaea andGlycine maxexhibited high ACE inhibition potential. The proteins from these five plants were extracted and hydrolyzed. Results revealed that protein extracted from Brassica napus exhibited highest ACE inhibition potential (70%), followed by Lens culnaris (69.07%), Arachis hypogaea (62.61%), Glycine max (58.42%) and Gossypium hirsutum (55.98%).The hydrolysis conditions for obtaining bioactives were optimized using resoponse surface methodology. Hydrolyzed proteinousfractionof Brassica napusshowed highest ACE inhibition potential (75%),followed by Lens culnaris, (67%), Glycine max (64%), Gossypium hirsutum (58%) and Arachis hypogaea (42%) All these five fractions showing significant ACE inhibitory activities, were characterized further by SDS-PAGE, LC-ESI-MS/MS and amino acid analyzer. SDS-PAGE revealed protein subunit of 39 kDa, 55 kDa and150 kDaby Glycine max, Lensculnaris and Arachis hypogaea respectively. While 25 kDa and 150 kDa protein subunits were found in Gossypium hirstum. Whereas 20, 55 and 150 kDa protein subunits were shown by Brassica napus. Results of LC-ESI-MS/MS analysis revealed SG, SP, MA, HA, KP, FT, ML, PR, APV, PAL, VMG, PLV, PPQ, HRAG, SFVL, AVHW, RTVR, HHYLV, DGACSANG and MVTGPGCH bioactive peptidesin the hydrolyzate of Glycine max. VG, TS, HT, HGG, FM, VPGG, KVW,EGASD, TVRMGand MTYYF were present in hydrolyzateof Gossypium hirsutum. AC, RS, FVG, RY, DDM, DPW, MLPA, MLLA, CDEV, NCNGR, DRGVCA, RDCVAD, HKYFM, YVWMDGbioactive peptides were found in Lense culnaris. Similarly ST, MV, ML, EF, ATF, ALPG, VAFG, DPME, VECY, ALLACPA and MCYYF were identified in hydrolyzed fraction of Brassica napus and VG, SS, SVG, FK, LPA, AGPL, VEPA, ELVA, YDPP and PDVYP from hydrolyzed Arachis hypogaea. Amino acid analysis showed that proteins ofboth Brassica napus and Lense culnariscontain sufficient quantity of vital amino acids which may have good hypotensive potential. Highest hypotensive potential of extracted proteins from Brassica napus and Lense culnariswas investigated through animal model. Brassica napus showed relatively lower but comparable therapeutic potential for lowering of BP. The results are encouraging due to the exploration of noval potent ACE inhibitory peptides from the indigenous plants. This may pave the way for new discovery of antihypertensive bioactive peptides.