title: Isolation and characterization of angiotensin I-converting enzyme inhibitory peptides derived from porcine hemoglobin.
abstract: Animal blood is potentially an untapped source of drugs and value-added food production. More than 400 million pigs are slaughtered each year but porcine blood is usually discarded in China. This study describes the isolation and characterization of angiotensin I-converting enzyme (ACE) inhibitory peptides derived from porcine hemoglobin. The most active hydrolysate was obtained from the peptic digestion of porcine hemoglobin. After the purification of ACE-inhibitory peptides with Sephadex LH-20 gel chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) on C(18) column, two active fractions were obtained. They were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). They were LGFPTTKTYFPHF and VVYPWT, corresponding to the 34-46 fragment of the alpha chain and the 34-39 fragment of the beta chain of porcine hemoglobin, with IC(50) values of 4.92 and 6.02 microM, respectively. They were the first found from porcine hemoglobin; in particular, LGFPTTKTYFPHF was a novel ACE-inhibitory peptide. In addition, the purified ACE inhibitors both competitively inhibited ACE, and maintained inhibitory activity even after incubation with gastrointestinal proteases. This suggests that these peptides might have a potential antihypertensive effect.
authors.affiliation: Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; Graduate School of the Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yike
authors.initials: Y
authors.lastname: Yu
authors.forename: Jianen
authors.initials: J
authors.lastname: Hu
authors.forename: Yuji
authors.initials: Y
authors.lastname: Miyaguchi
authors.forename: Xuefang
authors.initials: X
authors.lastname: Bai
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Du
authors.forename: Bingcheng
authors.initials: B
authors.lastname: Lin
mesh_terms: D000595:Amino Acid Sequence; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D000818:Animals; D006454:Hemoglobins / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry / Q000187:drug effects*; D011492:Protein Hydrolysates / Q000737:chemistry / Q000494:pharmacology; D013552:Swine
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D006454:Hemoglobins; D010455:Peptides; D011492:Protein Hydrolysates; D007703:Peptidyl-Dipeptidase A