• 한국자기공명학회논문지
• /
• 제2권2호
• /
• pp.141-151
• /
• 1998

Human annexin I is a member of annexin family of calcium dependent phospholipid binding proteins, which have been implicated in various physiological roles including phospholipase A2(PLA2) inhibition, membrane fusion and calcium channel activity. In this work, the structure of N-terminally truncated human annexin I ({{{{ DELTA }}-annexin I) and its interactions with Ca2+, ATP and cAMP were studied at atomic level by using nuclear magnetic resonance (NMR) spectroscopy. The effect of Ca2+ binding on the structure of {{{{ DELTA }}-annexin I was investigated. The addition of Ca2+ to {{{{ DELTA }}-annexin I caused some changes in 13C NMR spectra. Carbonyl carbon resonances of some histidines were significantly broadened by Ca2+ binding. However, in the case of methionine, phenylalanine, and tyrosin, small changes could be observed. We found that ATP and cAMP bind {{{{ DELTA }}-annexin I, and the binding ratio of ATP to {{{{ DELTA }}-annexin I is 1. These results are well consistent with the report that cAMP and ATP interact with annexin I, and affect the calcium channels formed by annexin I. Because {{{{ DELTA }}-annexin I is a large protein with 35 kDa molecular weight, site-specific (carbonyl-13C) labeling technique was used to study the interaction sites of {{{{ DELTA }}-annexin I with Ca2+. NMR study was focused on the carbonyl carbon resonances of tyrosine, phenylalanine, methionine and histidine residues of {{{{ DELTA }}-annexin I because the number of these amino acids is small in the amino acid sequence of {{{{ DELTA }}-annexin I.

• Journal of Nutrition and Health
• /
• 제30권10호
• /
• pp.1123-1131
• /
• 1997

This study examined the effect of dietary lipids and guar gum on lipid metabolism in ovariectomized rats. The experimental animals received ovarietomy (OVX). Lipids sources were divided into 3 groups (soybean oil(SB), beef tallow(BT)) and fish oil(FO)) and guar gum was supplemented to each lipid diet (SBG, BTG, FOG). Experimental diets were fed to therats for 16 weeks. Serum triglyceride (TG) levels were higher in the BT group and lower in the FO group as compared to the SB group .Serum total cholesterol (Tc) and HDL-C levels were lower in the FO group as compared to the SB group. Serum LDL-C and phospholipid levels were lower in the FO group as compared to the SB group. Serum lipids levels were lowered by guar gum supplement. Serum SFA(saturated fatty acids) contents were not significantly influenced by dietary lipids and guar gum. Serum MUFA(monounsaturated fatty acids) contents were the lowest in the SB group. Fecal weight was highest in the beef tallow group and lowest in the fish oil group. Fecal weight was increased by guar gum supplement in all lipid groups. Total bile acid content in feces was increased by guar gum supplement in the soybean oil and beef tallow groups. The endothelial cells of the beef tallow group changed from a flat shape to distorted round and enlarged shapes. The subendothelial layer was the thickness the thickest in the beef tallow group ; the interspace between elastic lamina was widened and elastic lamina was straightened and partly disrupted . The fish oil group showed more porminient endothelial cells and subendothelial layer. Internal elastic membrane and elastic lamina exhibited regularly wavy shapes. Guar gum supplement showed positive effects in all lipids groups. Based on the above results , it is suggested that beef tallow increased serum TG levels and injured the wall of the aorta. On the other hand, fish oil , which decreased serum lipid levels, has a positive effect on the walls of the aorta. Guar gum protects the aorta from injury by reducing the serum lipid levels. Therefore, it is suggested that soybean oil and beef tallow consumed with guar gum is beneficial.

• 식물조직배양학회지
• /
• 제24권4호
• /
• pp.197-201
• /
• 1997

Plant seed oil-bodies or oleosomes ate the repository of the neutral lipid stored in seeds. These organelles in many oilseeds may comprise half of the total cellular volume. Oleosomes are surrounded by a half-unit membrane of phospholipid into which are embedded proteins called oleosins. Oleosins are present at high density on the oil-body surface and after storage proteins comprise the most abundant proteins in oilseeds. Oleosins are specifically targeted and anchored to oil-bodies after co-translation on the ER. It has been shown that the amino-acid sequences responsible for this unique targeting reside primarily in the central hydrophobic tore of the oleosin polypeptide. In addition, a signal-like sequence is found near the junction of the hydrophobic domain and ann N-terminal hydrophilic / amphipathic domain. This "signal" which is uncleaved is also essential for correct targeting. Oil-bodies and their associated oleosins may be recovered by floatation centrifugation of aqueous seed extracts. This simple partitioning step results in a dramatic enrichment for oleosins in the oil-body fraction. In the light of these properties, we reasoned that it would be feasible to create fusion proteins on oil-bodies comprising oleosins and an additional valuable protein of pharmaceutical or industrial interest. It was further postulated that if these proteins were displayed on the outer surface of oil-bodies, it would be possible to release them from the purified oil-bodies using chemical or proteolytic cleavage. This could result in a simple means of recovering high-value protein from seeds at a significant (i.e. commercial) scale. This procedure has been successfully reduced to practice for a wide variety of proteins of therapeutic, industrial and food no. The utillity of the method will be discussed using a blood anticoagulant, hirudin, and industrial enzymes as key examples.

• Molecules and Cells
• /
• 제22권1호
• /
• pp.97-103
• /
• 2006

Phosphoinositides are critical regulators of ion channel and transporter activity. There are multiple isomers of biologically active phosphoinositides in the plasma membrane and the different lipid species are non-randomly distributed. However, the mechanism by which cells impose selectivity and directionality on lipid movements and so generate a non-random lipid distribution remains unclear. In the present study we investigated which structural elements of phosphoinositides are responsible for their subcellular location and movement. We incubated phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate ($PI(4,5)P_2$) with short or long acyl chains in CHO and HEK cells. We show that phosphate number and acyl chain length determine cellular location and translocation movement. In CHO cells, $PI(4,5)P_2$ with a long acyl chain was released into the cytosol easily because of a low partition coefficient whereas long chain PI was released more slowly because of a high partition coefficient. In HEK cells, the cellular location and translocation movement of PI were similar to those of PI in CHO cells, whereas those of $PI(4,5)P_2$ were different; some mechanism restricted the translocation movement of $PI(4,5)P_2$, and this is in good agreement with the extremely low lateral diffusion of $PI(4,5)P_2$. In contrast to the dependence on the number of phosphates of the phospholipid head group of long acyl chain analogs, short acyl chain phospholipids easily undergo translocation movement regardless of cell type and number of phosphates in the lipid headgroup.

• Bulletin of the Korean Chemical Society
• /
• 제33권1호
• /
• pp.115-122
• /
• 2012

Apidaecin Ib had strong antimicrobial activity against several tested Gram-negative bacteria including Escherichia coli, Enterobacter cloacae, and Shigella flexneri (MECs; $0.3-1.5{\mu}g/mL$), but showed no activity against all the tested Gram-positive bacteria including Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus and one yeast, Candida albicans (MECs; > $125{\mu}g/mL$). Interestingly, this peptide showed potent antibacterial activity only against Edwardsiella species (MECs; $0.6-3.6{\mu}g/mL$) among the tested fish pathogenic bacteria through a bacteriostatic process and showed no significant hemolytic activity. Apidaecin Ib took an unordered structure in all environments and also had very weak membrane perturbation activity even at $25{\mu}M$. Anti-Edwardsiella activity of apidaecin Ib is stronger than those of other antimicrobial polypeptides or antibiotics, but its activity is salt-sensitive. These results suggest that apidaecin Ib has Edwardsiella speciesspecific antibacterial activity and could be applied as new preventive or control additives for Edwardsiella species infection in freshwater fish aquaculture.

• Asian-Australasian Journal of Animal Sciences
• /
• 제32권8호
• /
• pp.1186-1194
• /
• 2019

Objective: The influence of broiler carcass scalding conditions on chicken breast meat quality parameters was investigated. Methods: Two hundred and seventy Cobb broiler chickens from 42 to 48 days old were slaughtered according to the standard industry practice and scalded in five temperature/time combinations-$T_1$, $54^{\circ}C/210s$; $T_2$, $55^{\circ}C/180s$; $T_3$, $56^{\circ}C/150s$; $T_4$, $57^{\circ}C/120s$; $T_5$, $58^{\circ}C/90s$. Results: Scalding temperature increase resulted in higher values of external and ventral lightness and in protein functionality reduction-determined by emulsification capacity and protein denaturation-in chicken breast fillets 24 h post-mortem. Protein secondary structures had conformational changes, with a decrease of the ${\alpha}$-helix and an increase of the ${\beta}$-sheet and ${\beta}$-turn proportions, mainly in $T_1$ and $T_5$ samples, determined by Fourier-transform infrared spectroscopy in an attenuated reflectance mode analysis. The chemical composition, pH, water holding capacity and Warner-Bratzler shear force did not differ among the treatments. In the fatty acid profile, the 18:1n-9 was lower in $T_5$, which suggested that the high scalding-temperature could have caused the lipid oxidation. The values of the polyunsaturated fatty acids (PUFA), such as 22:2, 20:4n-6, and 22:6n-3, were highest in the $T_5$, thus being related to the phospholipid cellular membrane collapse in this experimental condition and subsequent release of these PUFA. Conclusion: Intermediate scalding-parameters avoided the negative changes in the chicken meat quality.

• Journal of Microbiology and Biotechnology
• /
• 제31권1호
• /
• pp.115-122
• /
• 2021

Phenol-soluble modulins (PSMs) are responsible for regulating biofilm formation, persister cell formation, pmtR expression, host cell lysis, and anti-bacterial effects. To determine the effect of psm deletion on methicillin-resistant Staphylococcus aureus, we investigated psm deletion mutants including Δpsmα, Δpsmβ, and Δpsmαβ. These mutants exhibited increased β-lactam antibiotic resistance to ampicillin and oxacillin that was shown to be caused by increased N-acetylmannosamine kinase (nanK) mRNA expression, which regulates persister cell formation, leading to changes in the pattern of phospholipid fatty acids resulting in increased anteiso-C15:0, and increased membrane hydrophobicity with the deletion of PSMs. When synthetic PSMs were applied to Δpsmα and Δpsmβ mutants, treatment of Δpsmα with PSMα1-4 and Δpsmβ with PSMβ1-2 restored the sensitivity to oxacillin and slightly reduced the biofilm formation. Addition of a single fragment showed that α1, α2, α3, and β2 had an inhibiting effect on biofilms in Δpsmα; however, β1 showed an enhancing effect on biofilms in Δpsmβ. This study demonstrates a possible reason for the increased antibiotic resistance in psm mutants and the effect of PSMs on biofilm formation.

• 한국식품영양과학회지
• /
• 제24권6호
• /
• pp.867-873
• /
• 1995

만성적인 알코올 섭취가 미토콘드리아의 지질조성 및 ATPase 활성도에 미치는 영향을 조사하고 아울러 간의 발암물질인 2-AAF를 토여하여 간 미토콘드리아의 기능에 미치는 상호 효과를 조사하기 위하여 120~125g 숫쥐에게 열량의 35%를 알코올로 공급하여 6주간 사육하였으며 알코올 섭취 4주 후에 2-AAF를 3일 간격으로 2회 복강투여하여 실험한 결과를 요약하면 다음과 같다. 1. 체중 증가, 식이 섭취량 및 식이효율에 대한 알코올의 효과는 유의적인 차이를 보였으나, 2-AAF에 의한 유의적인 효과는 관찰할 수 없었다. 알코올 섭취군이 대조군 보다 체중은 유의적으로 감소하였다. 2. 미토콘드리아 ATPase 활성도는 알코올 섭취에 의해 유의적으로 감소되었고, 2-AAF 투여에 의해서는 유의적이지 않으나 감소되는 경향을 보였다. 따라서 대조군(C)에 비하여 알코올 섭취와 2-AAF투여군(EA)에서 ATPase 활성도가 29.3%의 감소를 나타냈다. 3. 간 미토콘드리아 콜레스테롤 함량은 알코올 섭취에 의해 유의적으로 증가하였으며 미토콘드리아 총 인지질량은 알코올과 2-AAF에 의한 상호작용에 의해 알코올 투여군에서만 2-AAF 투여시 유의적인 증가 효과를 보여주었다. C/PL 비율은 알코올 섭취와 2-AAF 투여 보두에서 유의적인 효과는 보이지 않았으나 군간 비교시 알코올군(E)이 대조군(C) 보다 유의적으로 증가하였다. 4. 간 미토콘드리아의 CL량은 알코올군에서 감소하는 경향을 보였고 PS와 PI량은 차이가 없었다. 알코올 섭취로 PC량은 유의적으로 증가하였으나 PE량은 차이가 없엇으며, 2-AAF 투여시 PC량은 유의적인 감소를 보였고 PE량은 유의적으로 증가하였다. PE/PC 비율은 알코올 투여에 의해 유의성은 없었으나 감소경향을 나타냈으며, 2-AAF 투여에 의해서는 유의적인 증가 효과가 나타났다. 5. 알코올 섭취시 미토콘드리아의 지방산 조성은 palmitic acid가 유의적으로 감소하였고, stearic acid는 유의적으로 증가함을 보였다. UFA/SFA와 UI는 알코올군에서 유의적이지는 않으나 증가되는 경향을 보였다. 2-AAF 투여에 의해서도 linoleic acid는 감소되고 arachidonic acid는 증가되는 경향을 보여 UI값이 증가되는 경향이 있었다. 따라서 본 실험에서 나타난 ATPase 호라성도 변화는 비토콘드리아의 콜레스테롤변화, C/PL 비율, 인지질 조성이나 지방산 조성의 변화 등 막지질 조성의 변화에 기인하는 것으로 생각된다.

• 대한화장품학회지
• /
• 제40권2호
• /
• pp.163-170
• /
• 2014

Phosphatidylcholine (PC) 인지질로 이루어진 모델 지질막은 세포막을 대신하여 지질막과 여러 분자간의 상호 작용을 연구하는 생물리 연구에 흔히 이용된다. 이들 모델 지질막을 제조하는 과정에서 지질 분자나 지질막과 작용하는 분자를 용해하는데 여러 가지 유기 용매가 이용된다. 용해 과정에 사용된 용매는 물론 제거되거나 소량 사용되기 때문에 실험 결과에 미치는 영향이 미미한 것으로 간주되어 보통 무시된다. 하지만 용매의 종류에 따라 소량의 용매가 용질 분자에 남아서 실험 결과에 영향을 미칠 수 있다. 본 연구에서는 시차열분석기와 인($^{31}P$) 고체 핵자기 공명 실험을 통하여 유기 용매가 지질막의 상변이와 지질막의 물리적 성질에 미치는 영향을 조사하였다. 클로로폼에 용해한 지질의 경우 비교적 쉽게 제거되었으며, 에탄올, trifluoroethanol(TFE) 또는 trifluoroacetic acid (TFA)에 용해한 분자들의 경우 용질에 잔류하여 지질과 용질의 상호작용시 지질의 물리적 성질에 영향을 미치는 것이 확인되었다. 따라서 지질막과 상호작용하는 분자들의 연구에서 용매의 선택이 중요하며 비록 미량이 사용되었을지라도 시료 제조와 실험 결과의 해석에 각별한 주의가 필요함을 보여 준다.

• Journal of Applied Biological Chemistry
• /
• 제60권3호
• /
• pp.271-277
• /
• 2017

에틸포메이트는 해충을 방제하기 위한 훈증제로서 사용되어 왔다. 그러나 농산업에서 해충을 박멸하기 위하여 사용된 이 물질이 일으키는 훈증독성의 작용점에 대해서는 많은 연구가 수행되지 않았다. 본 연구에서 저자들은 복숭아혹진딧물 약충에 에틸포메이트를 훈증 처리 하였을 때 추측 가능한 작용점들을 제시하였다. 에틸포메이트 훈증 처리 후 복숭아혹진딧물 약충에 대한 생화학 및 분자적 수준에서의 변화를 측정하였다. Cytochrome c oxidase (COX)의 활성은 에틸포메이트 훈증 처리된 복숭아혹진딧물 약충에서 약 2배 이상 증가하였다. Acetylcholinesterase (AChE)의 경우 에틸포메이트의 훈증 처리 농도가 증가됨과 함께 유전자 발현이 감소되었다. 이 두 발견은 COX와 AChE가 주요한 에틸포메이트 훈증독성의 작용점임을 시사하였다. 이 결과들과 함께 MALDI-TOF MS/MS를 이용하여 지질대사체를 분석한 후 2배 이상 증감을 보인 9종 인지질들을 동정하였고 이들이 세포막 조성에 변화를 유발함을 밝혔다. 결론적으로 복숭아혹진딧물 약충에 대한 에틸포메이트의 훈증독성은 COX 활성 변화, AChE 발현 변화, 그리고 인지질의 생성 변화에 기인하였다.