• Journal of Nutrition and Health
• /
• v.14 no.3
• /
• pp.124-128
• /
• 1981

This study was carried out to understand the activity of pepsin, the proteolytic enzyme, to octapeptide (angiotensin II) in the presence of various synthetic antioxidants as food additives. 1) Dibutyl hydroxy toluene, butyl hydroxyanisole and ethyl protocathechuate did not influence the inhibitory activity of pepsin an the octapeptide as a substrate, but sodium-L-ascorbate inhibited pepsin activity at above 100ppm. However sodium L-ascorbate was completely removed after 30 minutes. 2) Pepsin brought about a quick break up the octapeptide, Asp-Arg-Val-Tyr-Ile-His-Gly-Phe, by splitting the Gly-Phe and Val-Tyr bond. 3) The melting point of synthetized octapeptide was $209-212^{\circ}C$, chemical formula and molecula weight were $C_{43}H_{65}N_{13}O_{12}{\cdot}CH_3COOH{\cdot}H_2O$ and 956.05, respectively. 4) The amino acid mole ratio of synthetized octapeptide by acid hydrolysis were Asp:0.98, Arg: 1.02, Val: 1.00. Tyr: 0.95, Ile: 1.00, His: 1.03, Gly: 0.96, Phe: 1.00.

• Journal of Acupuncture Research
• /
• v.22 no.5
• /
• pp.57-66
• /
• 2005

Objectives : We examined the effects of electroacupuncture on the cholecystokinin-octapeptide-induced acute pancreatitis in rats. Methods : Rats were administered with $75{\mu}g/kg$ cholecystokinin-octapeptide subcutaneously three times (1, 3 and 5h after shaving) for 5days. Three days after finishing cholecystokinin-octapeptide administration, high frequency electroacupuncture (100Hz) and low frequency electroacupuncture (2Hz) were applied to acupoint equivalent to ST36 (Zusanli) for 7 days. The author determined the pancreatic weight/body weight ratio, the levels of pancreatic heat shock protein HSP60 and HSP72. The author also assay the secretion of ${\beta}-amylase$, lipase and pro-inflammatory cytokines in serum. Repeated cholecysokinin-octapeptide treatment resulted in the typical laboratory and morphological changes of experimentally induced pancreatitis. Results : Eelectroacupuncture significantly decreased the pancreatic weight/body weight ratio in cholecystokinin-octapeptide-induced acute pancreatitis, increased the pancreatic levels of HSP60 and HSP72, and decreased ${\beta}-amylase$ and lipase levels in cholecystokinin-octapeptide-induced acute pancreatitis. Additionally, the secretion of $Interleukin-1{\beta}$ and tumor necrosis $factor-{\alpha}$ was decreased in the animals treated with electroacupuncture. Conclusion : These results suggest that electroacupuncture may have protective effects against cholecystokinin-octapeptide-induced acute pancreatitis.

• Journal of the Korean Chemical Society
• /
• v.5 no.1
• /
• pp.33-37
• /
• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.

• Asian-Australasian Journal of Animal Sciences
• /
• v.2 no.3
• /
• pp.165-166
• /
• 1989

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.10a
• /
• pp.193-194
• /
• 2002

Angiotensin I converting enzyme (ACE) inhibitor was purified from Crassostrea gigas. The ACE belongs to the class of metalloprotease. This enzyme plays an important physiological role in regulating blood pressure of the rennin-angiotensin system by converting from angiotensin I to octapeptide angiotensin II, a potent vasoconstrictor and by inactivating bradykinin, which has depressor action. (omitted)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.10a
• /
• pp.171-172
• /
• 2001

체내에 널리 분포되어 있는 angiotensin 전환효소(angiotensin converting enzyme, ACE ; peptidyldipeptide hydrolase, EC 3.4.15.1)는 angiotensinogen이 renin의 특이적 분해를 받아서 생성된 불활성형인 angiotensin I의 말단 dipeptide(His-Leu)를 절단하여 octapeptide인 활성형의 angiotensin II로 전환시키며, 이렇게 생성된 angiotensin II는 직접적으로 혈압상승 작용을 하거나 adrenal로부터 sediumretaining steroid hormone인 aldosterone의 유리를 촉진시켜 체내 나트륨을 저류시킨다. (중략)

• Bulletin of the Korean Chemical Society
• /
• v.17 no.2
• /
• pp.182-188
• /
• 1996

Early attempts to identify plausible conformations of a linear octapeptide hormone, angiotensin-II (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe), using various theoretical and experimental methods, have led to various conformational models. So far, no consensus has been made about the solution phase structure and the receptor binding structure of angiotensin-II. The ultimate goal for the conformation study of the peptide hormone is to develop a new potent drug. Therefore, we have devised a strategy for designing the pharmacophore by studying thermodynamically possible conformations of various kinds of angiotensin-II antagonists and angiotensin-II.

• Archives of Pharmacal Research
• /
• v.21 no.6
• /
• pp.657-663
• /
• 1998

The enzyme responsible for the synthesis of nitric oxide (NO) from L-arginine in mammalian tissues is known as nitric oxide synthase (NOS) (EC.1.14.13.39). In the present study, the role of NO in the regulation of exocrine secretion was investigated in rat pancreatic acinar cells. Treatment of rat pancreatic acinar cells with cholecystokinin-octapeptide (CCK-OP) resulted in an increase in the arginine conversion to citrulline, the amount of $NO_X$, the release of amylase, and the level of CGMP. Especially, CCK-OP-stimulated increase of arginine to citrulline transformation, the amount of $NO_X$, and CGMP level were completely counteracted by the inhibitor of NOS, NG-monomethyl-L-arginine (MMA), by contrast, that of amylase release was partially reduced. Furthermore, MMA-induced decrease of NOS activity and amylase release showed dose-dependent pattern. The data on the time course of CCK-OP-induced citrulline formation and CGMP rise indicate that NOS and guanylate cyclase were activated by treatment of CCK-OP. However, the mechanism of agonist-stimulated guanylate cyclase activation in acinar cells remains unknown. Therefore, activation of NOS is one of the early events in receptor-mediated cascade of reactions in pancreatic acinar cells and NO, not completely, but partially mediate pancreatic enzyme exocrine secretion.

• BMB Reports
• /
• v.38 no.6
• /
• pp.646-649
• /
• 2005

Human neuronal growth inhibitory factor (GIF), a metalloprotein classified as metallothionein-3, is specifically expressed in mammal central nervous system (CNS). In these Studies the specific antibody to human GIF was prepared and used to search the epitope of human GIF by enzyme-linked immunosorbent assay (ELISA) and sequence comparison. The result of ELISA showed the epitope of human GIF may locate on a octapeptide (EAAEAEAE) in the $\alpha$-domain of human GIF, and the result of nerve cell culture indicated that the biological activity of GIF may be affected by the specific antibody.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.10a
• /
• pp.191-192
• /
• 2002

Angiotensin I converting enzyme [EC 3.4.15.11 (ACE) is important in the maintenance of blood pressure. The enzyme removes histidyl-leucine from angiotensin I to form the blood-vessel-constricting octapeptide, angiotensin II, and degrades vasodilative bradykinin in blood vessels and stimulates e release of aldosterone in the adrenal cortex. (omitted)