• Molecules and Cells
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• 제38권6호
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• pp.573-579
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• 2015

Apolipoprotein A-I and A-IV are protein constituents of high-density lipoproteins although their functional difference in lipoprotein metabolism is still unclear. To compare anti-atherogenic properties between apoA-I and apoA-4, we characterized both proteins in lipid-free and lipidbound state. In lipid-free state, apoA4 showed two distinct bands, around 78 and $67{\AA}$ on native gel electrophoresis, while apoA-I showed scattered band pattern less than $71{\AA}$. In reconstituted HDL (rHDL) state, apoA-4 showed three major bands around $101{\AA}$ and $113{\AA}$, while apoA-I-rHDL showed almost single band around $98{\AA}$ size. Lipid-free apoA-I showed 2.9-fold higher phospholipid binding ability than apoA-4. In lipid-free state, $BS_3$-crosslinking revealed that apoA-4 showed less multimerization tendency upto dimer, while apoA-I showed pentamerization. In rHDL state (95:1), apoA-4 was existed as dimer as like as apoA-I. With higher phospholipid content (255:1), five apoA-I and three apoA-4 were required to the bigger rHDL formation. Regardless of particle size, apoA-I-rHDL showed superior LCAT activation ability than apoA-4-rHDL. Uptake of acetylated LDL was inhibited by apoA-I in both lipid-free and lipid-bound state, while apoA-4 inhibited it only lipid-free state. ApoA-4 showed less anti-atherogenic activity with more sensitivity to glycation. In conclusion, apoA-4 showed inferior physiological functions in lipid-bound state, compared with those of apoA-I, to induce more pro-atherosclerotic properties.

• 생명과학회지
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• 제21권1호
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• pp.22-30
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• 2011

아포지방단백 A-I (apoA-I)은 항염증 및 항산화 작용을 가지고 있는 것으로 알려져 있다. 본 논문에서는 인간 혈액의 호중구를 이용하여 in vitro 상태에서 세포사멸과 시토카인의 분비 과정에 미치는 apoA-I의 영향을 조사하였다. 인간 호중구에 apoA-I을 처리한 결과 세포사멸의 정도가 감소되었다. 또한, apoA-I을 함유하는 고밀도 지방단백(HDL)에 의하여도 세포사멸은 현저히 감소되었다. HDL이 결합하는 수용체인 scavenger 수용체 B-1에 대한 항체에 의하여도 세포사멸은 억제되었다. ApoA-I을 20 시간 처리한 세포의 배양액내 인터루킨-8, 인터페론-유도단백질 10(IP-10) 및 종양괴사인자-α의 분비가 현저히 증가하였다. 호중구에 인터페론 감마와 apoA-I을 동시 처리하였을 때 시토카인 중에서 IP-10과 종양괴사인자-$\alpha$의 분비가 단독으로 처리한 경우에 비해 현저히 증가되었다. 이러한 결과들은 인간 혈액 호중구에 apoA-I을 처리한 경우 호중구가 활성화되고 호중구의 세포사멸이 지연된다는 것을 제시하는 것으로 apoA-I이 호중구에 대하여 염증성 인자로 작용할 것으로 추정된다.

• BMB Reports
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• 제30권6호
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• pp.390-396
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• 1997

A sandwich-type enzyme-linked immunosorbent assay (ELISA) for the quantification of human apolipoprotein A-I (apoA-I) was developed using monoclonal antibodies. For this assay, we used three monoclonal antibodies to trap and detect apo A-I. HDAI16 and HDA15 monoclonal antibodies were used for trapping apoA-I and HDAI8 monoclonal antibody was for detecting apoA-I. These three monoclonal antibodies were produced by immunizing mice with high density lipoprotein (HDL) isolated from human plasma. By immunoblot analysis, these three monoclonal antibodies were specific to apoA-I and showed no cross-reactivities with other plasma proteins. The results of competition assays for epitope cross-reactivity test also verified that these monoclonal antibodies identified separate and distinct epitopes on HDL and apoA-I. Affinity constants of monoclonal antibodies were measured by ELISA. Their association constants ranged from $10^7$ to $10^8$ $M^{-1}$. For this assay, pure apoA-I was isolated by affinity chromatography using monoclonal antibodies. In this sandwich assay, the amount of HRP-labeled HDAI8 bound to apoA-I trapped by HDAI16 and HDAI5 was proportional to apoA-I concentration in the range of 0 to 500ng/ml. ApoA-I concentration in plasma was calculated from the linear regression equation of standard curve. The precision and reliability of the assays are reflected in the low intra-and interassay coefficients of variation that averaged 3.25% and 4.30%, respectively. This assay is sensitive, simple, reproducible, convenient in incubation interval, and does not use radioisotope: thus it can be widely applied in clinical laboratories.

• Molecules and Cells
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• 제27권3호
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• pp.291-297
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• 2009

Apolipoprotein (apo) C-III is a marker protein of triacylglycerol (TG)-rich lipoproteins and high-density lipoproteins (HDL), and has been proposed as a risk factor of coronary heart disease. To compare the physiologic role of reconstituted HDL (rHDL) with or without apoC-III, we synthesized rHDL with molar ratios of apoA-I:apoC-III of 1:0, 1:0.5, 1:1, and 1:2. Increasing the apoC-III content in rHDL produced smaller rHDL particles with a lower number of apoA-I molecules. Furthermore, increasing the molar ratio of apoC-III in rHDL enhanced the surfactant-like properties and the ability to lyse dimyristoyl phosphatidylcholine. Furthermore, rHDL containing apoC-III was found to be more resistant to particle rearrangement in the presence of low-density lipoprotein (LDL) than rHDL that contained apoA-I alone. In addition, the lecithin:cholesterol acyltransferase (LCAT) activation ability was reduced as the apoC-III content of the rHDL increased; however, the CE transfer ability was not decreased by the increase of apoC-III. Finally, rHDL containing apoC-III aggravated the production of MDA in cell culture media, which led to increased cellular uptake of LDL. Thus, the addition of apoC-III to rHDL induced changes in the structural and functional properties of the rHDL, especially in particle size and rearrangement and LCAT activation. These alterations may lead to beneficial functions of HDL, which is involved in anti-atherogenic properties in the circulation.

• 한국양식학회지
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• 제20권1호
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• pp.65-72
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• 2007

우리나라 주요 담수어종인 미꾸라지(Misgurnus mizolepis)로 부터 apolipoprotein A-I (apoA-I) cDNA를 분리하고 그 구조, 분자 계통 및 발현 특징을 분석하였다. 미꾸라지 apoA-I cDNA는 254개의 아미노산을 암호화하고 있는 762 bp의 ORF를 포함하고 있었으며 아울러 24 bp의 5'UTR 및 293 bp의 3'UTR(종결 코돈 및 poly A tail 제외)를 갖고 있었다. 미꾸라지 apoA-I은 여타 척추동물 apoA-I과의 다중배열 시 염기서열에서는 많은 차이를 나타내었지만 단백질의 구조적 특징은 높은 상동성을 보였고, 또한 척추동물의 apoA-I들과의 분자계통을 분석한 결과, 종래 알려진 분류학적 위치와 비교적 잘 일치하였다. 미꾸라지 apoA-I mRNA는 RT-PCR 분석을 통해 간 및 뇌 조직에서 분석한 다른 조직보다 유의적으로 높게 발현하는 것으로 나타났고, 특히 간에서 가장 높은 발현을 보였다. 수정시부터 부화 후 14일까지 초기 발생 및 치어에서의 apoA-I mRNA 발현을 조사한 결과 수정 8시간째부터 급격한 발현의 증가가 시작되어 이후 지속적으로 높은 발현 수준을 유지하였다.

• Fisheries and Aquatic Sciences
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• 제11권2호
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• pp.88-97
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• 2008

Lipoproteins are complexes of lipids and specific apolipoproteins that are involved in lipid transport and redistribution among various tissues. In this study, we isolated full-length apolipoprotein cDNA sequences encoding apolipoprotein A-I (apoA-I), apoE, apoC-II, and apo-14 kDa in barred knifejaw, Oplegnathus fasciatus. In addition, we reconstructed phylogenetic trees and investigated mRNA tissue distributions. Alignment analyses of amino acid sequences revealed that secondary structures of the polypeptides apoA-I, apoE, and apoC-II in barred knifejaw are well conserved with their teleostean and mammalian counterparts in terms of characteristic tandem repetitive units forming amphipathic ${\alpha}$-helices. Both the sequence alignment data and cleavage sites of apo-14 kDa indicated a clear differentiation between Percomorpha and Cypriniformes. Meanwhile, the phylogenetic trees of apolipoprotein sub-families suggested that the common ancestor prior to the split of the Actinopterygii (ray-finned fishes) and Sarcopterygii (tetrapods) would have possessed the primordial protein-encoding genes. Tissue distribution of each apolipoprotein transcript determined by semi-quantitative RTPCR showed that barred knifejaw apoA-I transcripts were more or less ubiquitously expressed in the liver, intestines, brain, muscle, spleen, and kidney. The most striking difference from previous observations on barred knifejaw was the ubiquitous expression of apoE across all somatic tissues. Barred knifejaw apoC-II showed tissue-specific expression in the liver and intestines, while the liver and brain were the major sites of apo-14kDa mRNA synthesis.

• Molecules and Cells
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• 제26권3호
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• pp.291-298
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• 2008

Human karyopherin ${\beta}3$, highly homologous to a yeast protein secretion enhancer (PSE1), has often been reported to be associated with a mediator of a nucleocytoplasmic transport pathway. Previously, we showed that karyopherin ${\beta}3$ complemented the PSE1 and KAP123 double mutant. Our research suggested that karyopherin beta has an evolutionary function similar to that of yeast PSE1 and/or KAP 123. In this study, we performed yeast two-hybrid screening to find a protein which would interact with karyopherin ${\beta}3$ and identified apolipoprotein A-I (apo A-I), a secretion protein with a primary function in cholesterol transport. By using in vitro binding assay, co-immunoprecipitation, and colocalization studies, we defined an interaction between karyopherin ${\beta}3$ and apo A-I. In addition, overexpression of karyopherin ${\beta}3$ significantly increased apo A-I secretion. These results suggest that karyopherin ${\beta}3$ plays a crucial role in apo A-I secretion. These findings may be relevant to the study of a novel function of karyopherin ${\beta}3$ and coronary artery diseases associated with apo A-I.

• Bulletin of the Korean Chemical Society
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• 제32권9호
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• pp.3425-3428
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• 2011

Apolipoprotein A-I (Apo A-I) is a major component for high density lipoproteins (HDL). A number of mimetic peptides of Apo A-I were screened from the phase-displayed random peptide library by utilizing monoclonal antibodies (A12). Mimetic peptide for A12 epitope against Apo A-I was selected as CPFARLPVEHHDVVGL (pA1). From the BLAST search, the mimetic peptide pA1 had 40% homology with Apo A-I. As a result of the structural determination of this mimotope using homo/hetero nuclear 2D-NMR techniques and NMR-based distance geometry (DG)/molecular dynamic (MD) computations, DG structure had low penalty value of 0.3-0.7 ${\AA}^2$ and the total RMSD was 0.6-1.6 ${\AA}$. The mimotope pA1 exhibited characteristic conformation including a ${\beta}$-turn from Pro[7] to His[11].

• Journal of Preventive Medicine and Public Health
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• 제40권1호
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• pp.71-76
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• 2007

Objectives : This study was performed to investigate the distribution of apolipoproteins A-I and B among Korean employees and their partners. Methods : The study population consisted of 7,633 men and women (4,578 men and 3,054 women) residing in Seoul and Kyung-gee Do, with an average age of $43.5{\pm}8.3$ years. Blood samples were collected following at least 12 hours of fasting. Apolipoproteins A-I and B were measured using a Behring Nephelometer analyzer. The body mass index (BMI) for each participant was calculated as weight (kg) divided by height squared $(m^2)$. Information on health-related behaviors such as exercise, alcohol intake, and smoking habits was collected through self-administrated questionnaires. Results : The mean concentrations of Apo A-I were $132.6{\pm}22.3mg/dL$ and $142.9{\pm}24.8mg/dL$ in the men and women, respectively. The concentration of Apo A-I increased significantly across all age categories of men. The mean concentrations of Apo B were $101.7{\pm}23.2mg/dL$ and $87.8{\pm}23.5mg/dL$ in the men and women, respectively, and Apo B increased significantly across all age categories for both the men and women. Exercise and BMI were major determinants for Apo A-I and B levels. The 10th percentile of Apo A-I concentration was 109 mg/dL in the men and 113 mg/dL in the women, and the 90th percentile of Apo B concentration was 131 mg/dL in the men and 118 mg/dL women. Conclusions : For the prevention of coronary artery disease, we recommend that for individuals in the 10th percentile of concentration for Apo A-I and the 90th percentile of concentration for Apo B, active preventive interventions such as weight loss and exercise should be taken. This study, within its limitations, may be useful for evaluating apolipoprotein A-I and B concentrations in Korean adults.

• 동의생리병리학회지
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• 제18권4호
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• pp.1192-1198
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• 2004

Sasang Constitutional Medicine is a major branch of Korean Traditional Medicine. The differences of disease susceptibility to be shown in Sasang constitution may be due to genetic factors. Therefore, I examined interrelationship among cerebral infarction (CI), apolipoprotein E (apo E) gene polymorphism, and Sasang constitutional classification. Apo E is a key protein modulating the highly atherogenic apoB containing lipoproteins and is a candidate gene for the development of coronary artery disease (CAD). The ε2 and/or ε4 alleles were the first to be implicated in premature CAD, which resulted in this polymorphism being extensively studied. I investigated the association between apo E genotype and CI by case-control study in a Korean population. I also classified CI patients and control group into groups according to Sasang Constitutional Medicine. 218 CI patients and 379 controls without CI were examined. Apo E genotype was determined by 8% polyacrylamide gel separation after DNA amplification. A frequency of apo E ε3/ε3 in the apo E genotype distribution was higher in the CI patients compared with that in controls. Also, it was widely known that Taeumin was easily attacked with CI, but there was no association between apo E polymorphim and Taeumin. However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with apo E ε2 and/or ε4 alleles. No differences in the apo E genotypes frequencies were observed in the Taeumin compared with that in the other constitutions. In addition, I investigated whether the DD(deletion/deletion) or ID(insertion/deletion) genotype of angiotensin converting enzyme (ACE) gene, a candidate gene for CI, was associated with CI, Taeumin constitution, and apo E polymorphism. As a result, the frequency of Taeumin constitution was significantly higher in CI patients with both apo E ε3/ε4 and ACE ID/DD genotypes than in the remaining Sasang constitutions. In summary, it was concluded that the apo E polymorphism is a major risk factor for CI in Koreans and the ACE ID/DD genotype enhanced the relative risk for CI in the subjects with apo E ε3/ε4 genotype and Taeumin constitution.