• BMB Reports
• /
• 제42권1호
• /
• pp.47-52
• /
• 2009

Alanine racemase catalyzes the interconversion of L-alanine and D-alanine and plays a crucial role in spore germination and cell wall biosynthesis. In this study, alanine racemase produced by Bacillus anthracis was expressed and purified as a monomer in Escherichia coli and the importance of lysine 41 in the cofactor binding octapeptide and tyrosine 270 in catalysis was evaluated. The native enzyme exhibited an apparent $K_m$ of 3 mM for L-alanine, and a $V_{max}$ of $295\;{\mu}moles/min/mg$, with the optimum activity occurring at $37^{\circ}C$ and a pH of 8-9. The activity observed in the absence of exogenous pyridoxal 5'-phosphate suggested that the cofactor is bound to the enzyme. Additionally, the UV-visible absorption spectra indicated that the activity was pH independece, of VV-visible absorption spectra suggests that the bound PLP exists as a protonated Schiff's base. Furthermore, the loss of activity observed in the apoenzyme suggested that bound PLP is required for catalysis. Finally, the enzyme followed non-competitive and mixed inhibition kinetics for hydroxylamine and propionate with a $K_i$of $160\;{\mu}M$ and 30 mM, respectively.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권3호
• /
• pp.821-825
• /
• 2012

Purpose: Centromere protein H (CENP-H) and Ki67 are overexpressed in some malignancies, but whether they are predictors of survival after primary resection for hypopharyngeal squamous cell carcinoma (HSCC) remains unknown. Methods: We assessed immunohistochemical expression of CENP-H and Ki67 in 112 HSCC specimens collected between March 2003 and March 2005 for analysis by clinical characteristics. The Kaplan-Meier method was used to analyze relapse-free survival and logistic multivariate regression to determine risk factors of relapse-free survival. Cholecystokinin octapeptide assays and flow cytometry were used to examine cell proliferation and apoptosis after siRNA inhibition of CENP-H in HSCC cells. Results: Overall, 50 (44.6%) HSCC specimens showed upregulated CENP-H expression and 69 (61.6%) upregulated Ki67. An increased CENP-H protein level was associated with advanced cancer stage and alcohol history (P=0.012 and P=0.048, respectively) but an increased Ki67 protein level only with advanced cancer stage (P=0.021). Increased CENP-H or Ki67 were associated with short relapse-free survival (P<0.001 or P=0.009, respectively) and were independent predictors of relapse-free survival (P=0.001 and P=0.018, respectively). siRNA knockdown of CENP-H mRNA inhibited cell proliferation and promoted cancer cell apoptosis in vitro. Conclusions: Upregulated CENP-H and Ki67 levels are significantly associated with short relapse-free survival in HSCC. These factors may be predictors of a relapsing phenotype in HSSC cases.

• 대한한방소아과학회지
• /
• 제20권3호
• /
• pp.117-127
• /
• 2006

Objectives : In this study, we investigated the effects of Daehwangmokdanpitang-gagambang(DMG) on treatment for cholecystokinin-octapeptide(CCK)-induced acute pancreatitis(AP) in rats. Methods : Male Wistar rats weighing 200 to 250 g were divided into three groups. The first was normal untreated group, the second was in treatment with DMG group; DMG was administered orally, followed by 75 ${\mu}g/kg$ CCK subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 days. The third was in treatment with saline group, the protocol was the same as in treatment group with DMG. We determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60, HSP72, ERK, p38 MAPK and the secretion of pro-inflammatory cytokines. Repeated CCK treatment resulted in the typical laboratory and morphological changes of experimentally induced pancreatitis. Results : DMG was significantly decreased the pancreatic weight/body weight ratio in CCKinduced AP and DMG increased HSP60 and HSP72 compared with CCK-induced AP. DMG suppressed ERK and p38 MAPK activation. Additionally, the secretion of $IL-1{\beta}$ and $TNF-{\alpha}$ and the levels of amylase and lipase were lower than that saline. Conclusions : DMG has an effect to treatment for CCK-induced AP.

• 한국결정학회:학술대회논문집
• /
• 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
• /
• pp.4-4
• /
• 2002

PDZ domains bind to short segments within target proteins in a sequence-specific fashion. GRIP/ABP family proteins contain six to seven PDZ domains and interact via its sixth PDZ domain (class Ⅱ) with the C-termini of various proteins, including liprin-α. In addition the PDZ456 domain mediates the formation of homo- and heteromultimers of GRIP proteins. To better understand the structural basis of peptide recognition by a class Ⅱ PDZ domain and DZ-mediated multimerization, we determined the crystal structures of the GRIPI PDZ6 domain, alone and in complex with a synthetic C-terminal octapeptide of human liprin-α, at resolutions of 1.5 Å and 1.8 Å, respectively. Remarkably, unlike other class Ⅱ PDZ domains, Ile736 at αB5 rather than conserved Leu732 at αB1 makes a direct hydrophobic contact with the side chain of the Tyr at the -2 position of the ligand. Moreover, the peptide-bound structure of PDZ6 shows a slight reorientation of helix αB, indicating that the second hydrophobic pocket undergoes a conformational adaptation to accommodate the bulkiness of the Tyr's side chain, and forms an antiparallel dimer through an interface located at a site distal to the peptide-binding groove. This configuration may enable formation of GRIP multimers and efficient clustering of GRIP-binding proteins.

• 대한본초학회지
• /
• 제20권3호
• /
• pp.93-100
• /
• 2005

Objective : Patriniae Herba (PH) has long been used as a remedy for treating infectious diseases in Korea. In the present experiments, the author examined the effects of PH on the cholecystokinin-octapeptide (CCK)-induced acute pancreatitis (AP) in rats. Methods : Male Wistar rat weighing 200 to 250 g were divided into three groups. Normal untreated group, in treatment with PH group; PH (1g/kg) was administered orally, followed by $75\;{\mu}g/kg$ CCK subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 days. In treatment with saline group, the protocol was the same as in treatment group with PH. The author determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP60, HSP72 and the secretion of pro-inflammatory cytokines. Methods : Repeated CCK treatment resulted in the typical laboratory and morphological changes of experimentally induced pancreatitis. PH was significantly decreased the pancreatic weight/body weight ratio in CCK-induced AP. Futhermore, the author demonstrated that PH increased HSP60 and HSP72 compared with CCK-induced AP. Additionally, the secretion of $TNF-{\alpha},\;IL-1{\beta}$ and IL-6 the levels of amylase and lipase were lower than that saline. Conclusions : These results suggest that PH may has a inhibitory effect against CCK-induced AP.

• 대한본초학회지
• /
• 제20권3호
• /
• pp.59-65
• /
• 2005

Objective : Daehwangmokdanpi-Tang (DWT) has been frequently used as a remedy for antiinflamation. To evaluate effect of acute pancreatitis by DWT, we examined the effects of DWT on the cholecystokinin-octapeptide (CCK)-induced acute pancreatitis (AP) in rats. Methods : Male Wistar rats weighing 200 to 250 g were divided into three groups. Normal untreated group, in treatment with DWT group; DWT was administered orally, followed by $75\;{\mu}g/kg$ CCK subcutaneously three times, after 1, 3 and 5 h. This whole procedure was repeated for 5 days. In treatment with saline group, the protocol was the same as in treatment group with DWT. Results : The author determined the pancreatic weight/body weight ratio, the levels of pancreatic HSP (heat shock protein)60 and HSP72 and the secretion of pro-inflammatory cytokines. Repeated CCK treatment resulted in the typical laboratory and morphological changes of experimentally induced pancreatitis. DWT was significantly decreased the pancreatic weight/body weight ratio in CCK-induced AP. Futhermore, The author demonstrated that DWT increased HSP60 and HSP72 compared with CCK-induced AP. Additionally, the secretion of $IL-1{\beta}\;and\;TNF-{\alpha}$ and the levels of amylase and lipase were lower than that saline. Conclusions : These results suggested that DWT may has a protective effect against CCK-induced AP.

• 디지털융복합연구
• /
• 제20권2호
• /
• pp.311-316
• /
• 2022

Tertomotide는 hTert의 일부분이며 항암 백신으로 개발된 펩타이드이나 임상시험과 동물실험에서 염증성 질환을 개선하는 활성이 다수 보고된 바 있다. 다양한 연구에서 발견된 항염활성에도 불구하고 약물성이 높지 않아 일반적인 항염약물로의 개발이 어렵다. 다양한 부위에서 일어나는 염증성 증상에 활용하기 위해서는 항염활성과 약물성이 동반되어야 하므로 구조의 개선이 필요하다. 본 연구에서는 tertomotide의 구조를 기반으로 12 종의 옥타펩타이드를 설계하고 항염증 활성을 측정하여 약물성이 개선된 tertomotide 유래의 항염 펩타이드를 도출하고자 하였다. 이를 위해 활성화된 단핵구에서 염증성 cytokine인 TNF-α의 분비에 미치는 영향을 측정하여 각 펩타이드의 항염 활성을 평가하였고 양성대조군으로 비교한 estradiol이나 tertomotide 이상의 항염활성을 가진 펩타이드를 도출하였다. 본 연구의 결과는 tertotmotide 유래 펩타이드들을 활용한 신규 항염증 소재 개발 연구에 도움이 될 것으로 예상되며, 항염증 활성 등의 생리활성이 있으나 약물성이 낮은 펩타이드에 대해 계산화학적 접근으로 구조를 변경하여 기능적 잠재력 있는 신규활성물질을 도출하는 융합연구의 좋은 예가 될 것으로 사료된다.

• International Journal of Oral Biology
• /
• 제31권4호
• /
• pp.127-133
• /
• 2006

[ $H_2O_2$ ], a member of reactive oxygen species (ROS), is known to be involved in the mediation of physiological functions in a variety of cell types. However, little has been known about the physiological role of $H_2O_2$ in exocrine cells. Therefore, in the present study, the effect of $H_2O_2$ on cholecystokinin (CCK)-evoked $Ca^{2+}$ mobilization and amylase release was investigated in rat pancreatic acinar cells. Stimulation of the acinar cells with sulfated octapeptide form of CCK (CCK-8S) induced biphasic increase in amylase release. Addition of $30\;{\mu}M\;H_2O_2$ enhanced amylase release caused by 10 pM CCK-8S, but inhibited the amylase release induced by CCK-8S at concentrations higher than 100 pM. An ROS scavenger, $10\;{\mu}M$ Mn(III)tetrakis(4-benzoic acid)porphyrin chloride, increased amylase release caused by CCK-8S at concentrations higher than 100 pM, although lower concentrations of CCK-8S-induced amylase release was not affected. To examine whether the effect of $H_2O_2$ on CCK-8S-induced amylase release was exerted via modulation of intracellular $Ca^{2+}$ signaling, we measured the changes in intracellular $Ca^{2+}$ concentration $([Ca^{2+}]_i)$ in fura-2 loaded acinar cells. Although $30\;{\mu}M\;H_2O_2$ did not induce any increase in $[Ca^{2+}]_i$ by itself, it increased the frequency and amplitude of $[Ca^{2+}]_i$ oscillations caused by 10 pM CCK-8S. However, $30\;{\mu}M\;H_2O_2$ had little effect on 1 nM CCK-8S-induced increase in $[Ca^{2+}]_i$. ROS scavenger, 1 mM N-acetylcysteine, did not affect $[Ca^{2+}]_i$ changes induced by 10 pM or 1 nM CCK-8S. Therefore, it was concluded that $30\;{\mu}M\;H_2O_2$ enhanced low concentration of CCK-8S-induced amylase release probably by increasing $[Ca^{2+}]_i$ oscillations while it inhibited high concentration of CCK-8S-induced amylase release.

• 대한약리학회지
• /
• 제20권2호
• /
• pp.49-57
• /
• 1984

The exocrine pancreatic secretion is controlled mainly by gastrointestinal hormones as well as cholinergic nerves. The adrenergic influence on exocrine pancreas is thought not to he important and the evidences supporting this contention are still contradictory. In an effort to elucidate the adrenergic influence on the exocrine pancreas, we have determined the amylase release from pancreatic slices of rats treated with adrenergic drugs. The albino rats of either sex, weighing $60{\sim}80\;g$, were decapitated and the uncinate pancreata were isolated and incubated in screw top vials containing 2 ml krebs-Ringer bicarbonate buffer solution gassed with 95% $O_2$ and 5% $CO_2$. These vials were shaken continuously in a waterbath maintained at $37^{circ}C$, and enzyme release was stimulated with acetylcholine$(10^{-5}M)$. For chronic treatment methoxamine$(an\;{\alpha}-adrenergic\;agonist,\;5\;mg/kg)$, isoproterenol (a\;{\beta}-adrenergic\;agonist,\;10\;mg/kg) and reserpine (0.5 mg/kg) along with cholecystokinin octapeptide$(CCK-op,\;2{\mu}g/kg)$ were given i.p. in rats daily for 3, 5, 7, 9 or 12 days. For acute experiment these drugs were added directly to the incubation medium in a concentration of $10^{-5}M$ except CCK-OP $(10^{-9}M)$. The results are summarized as follows. 1) The addition of methoxamine, isoproterenol or reserpine to the incubation medium containing pancreatic slices augmented the release of amylase induced by acetylcholine and among them the effect of isoproterenol was most prominent. 2) Chronic treatment of methoxamine or reserpine caused enhancement of acetylcholine response in amylase release from pancreatic slice throughout the experimental period, but the amylase release was less than that of control by 12 days isoproterenol treatment. 3) In the pancreatic slices obtained from 12 days treatment of CCK-OP, the amylae release responding to acetylcholine was enhanced. By these finding it is suggested that methoxamine, isoproterenol and reserpine had marked influence on the exocrine pancreatic functions in rats and that these effects are due to their inherent actions rather than sympathetic nerve or adrenergic receptor function.