title: Angiotensin I-converting enzyme-inhibitory peptides obtained from chicken collagen hydrolysate.
abstract: In this study, collagen extracted from chicken legs (which are the yellow keratin parts containing a nail) was hydrolyzed with various enzymes, and the angiotensin I-converting enzyme (ACE)-inhibitory activity of each hydrolysate was determined. The hydrolysate by treatment with an Aspergillus species-derived enzyme had the highest activity (IC 50 = 260 microg/mL). The fraction of this hydrolysate obtained by ultrafiltration with a molecular-weight cutoff of 3000 Da (low fraction) had a stronger activity (IC 50 = 130 microg/mL) than the fractionated one. This fraction was further fractionated by HPLC, and the peptides in the fraction with high ACE-inhibitory activity were identified. The amino acid sequences of the four peptides were identified using a protein sequencer. These peptides were synthesized to confirm their ACE-inhibitory activities; this showed that peptides with a Gly-Ala-Hyp-Gly-Leu-Hyp-Gly-Pro sequence had the highest activity (IC 50 = 29 microM). When the low fraction was administered to spontaneous hypertensive rats, a decrease in their blood pressure was observed after 2 h of administration, and a significant decrease in blood pressure (-50 mmHg) was observed after 6 h. Moreover, long-term administration studies indicated that the low fraction showed a significant suppression of increased blood pressure.
authors.affiliation: Research and Development Center, Nippon Meat Packers, Incorporated, Tsukuba, Ibaraki 300-2646, Japan. a.egusa@nipponham.co.jp
authors.forename: Ai
authors.initials: A
authors.lastname: Saiga
authors.forename: Koji
authors.initials: K
authors.lastname: Iwai
authors.forename: Toru
authors.initials: T
authors.lastname: Hayakawa
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Takahata
authors.forename: Shiniich
authors.initials: S
authors.lastname: Kitamura
authors.forename: Toshihide
authors.initials: T
authors.lastname: Nishimura
authors.forename: Fumiki
authors.initials: F
authors.lastname: Morimatsu
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001794:Blood Pressure; D002645:Chickens; D003094:Collagen / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D008297:Male; D013058:Mass Spectrometry; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D011492:Protein Hydrolysates / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D011918:Rats, Inbred SHR
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D010455:Peptides; D011492:Protein Hydrolysates; D003094:Collagen; D007703:Peptidyl-Dipeptidase A