• 생명과학회지
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• 제13권4호
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• pp.463-472
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• 2003

제5인자와 지질막 phosphatidylserine과의 상호작용은 prothrombinase 복합체의 활성을 조절하는데 중요하다. 본 연구에서 제5인자의 지질 결합부위에 위치한 Trp2063과 Trp2064를 동시에 돌연변이 시킨 재조합 제5인자를 과발현 시키고 정제하였다. 돌연변이된 제5인자는 1-10%의 phosphatidylserine을 포함하는 지질막에서 아주낮은 활성을 보였다. surface plasmon resonance에 의해서 지질막과의 결합을 측정한 결과 돌연변이된 제5인자가 본래의 제5인자보다 고정된 지질막에의 결합이 현저하게 떨어지는 것을 관찰하였다. 제5인자가 phosphatidylserine을 포함하는 지질막에 높은 친화력으로 결합하기 위해서는 Trp2063과 Trp2064가 필수적이고 이러한 상호작용은 생리적인 phosphatidylserine 농도를 포함하는 지질막 위에서 prothrombinase 복합체의 형성에 필요하다는 결론을 내렸다.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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• pp.408-413
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• 2006

A strain, P821, with phospholipase D activity was isolated from soil and identified as a Streptomyces species. The phospholipase D enzyme was purified from a culture broth of the isolated strain using ammonium sulfate precipitation and DEAE-Sepharose, phenyl-Sepharose, and Superose 12 HR column chromatographies. The purified enzyme exhibited an optimum temperature and pH of $55^{\circ}C$ and 6.0, respectively, in the hydrolysis of phosphatidylcholine and remained stable up to $60^{\circ}C$ within a pH range of 3.5-8.0. The enzyme also catalyzed a transphosphatidylation reaction to produce phosphatidylserine with phosphatidylcholine and serine substrates. The optimum conditions for the transphosphatidylation were $30^{\circ}C$ and pH 5.0, indicating quite different optimum conditions for the hydrolysis and transphosphatidylation reactions. The gene encoding the enzyme was cloned by Southern hybridization and colony hybridization using a DNA probe designed from the conserved regions of other known phospholipase D enzymes. The resulting amino acid sequence was most similar to that of the PLD enzyme from Streptomyces halstedii (89.5%). Therefore, the enzyme was confirmed to be a phospholipase D with potential use in the production of phosphatidylserine.

• BMB Reports
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• 제49권6호
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• pp.303-304
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• 2016

Myoblast fusion is important for skeletal muscle formation. Even though the knowledge of myoblast fusion mechanism has accumulated over the years, the initial signal of fusion is yet to be elucidated. Our study reveals the novel function of a phosphatidylserine (PS) receptor, stabilin-2 (Stab2), in the modulation of myoblast fusion, through the recognition of PS exposed on myoblasts. During differentiation of myoblasts, Stab2 expression is higher than other PS receptors and is controlled by calcineurin/NFAT signaling on myoblasts. The forced expression of Stab2 results in an increase in myoblast fusion; genetic ablation of Stab2 in mice causes a reduction in muscle size, as a result of impaired myoblast fusion. After muscle injury, muscle regeneration is impaired in Stab2-deficient mice, resulting in small myofibers with fewer nuclei, which is due to reduction of fusion rather than defection of myoblast differentiation. The fusion-promoting role of Stab2 is dependent on its PS-binding motif, and the blocking of PS-Stab2 binding impairs cell-cell fusion on myoblasts. Given our previous finding that Stab2 recognizes PS exposed on apoptotic cells for sensing as an "eat-me" signal, we propose that PS-Stab2 binding is required for sensing of a "fuse-me" signal as the initial signal of myoblast fusion.

• 한국식품과학회지
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• 제54권1호
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• pp.52-58
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• 2022

Phosphatidylserine (PS) is an essential component of the cerebral cortex and is associated with cognitive function. In this systematic review, the effects of PS on cognitive function in the elderly population are examined. The literature search included PubMed, EMBASE, Cochrane, and Web of Science databases. Subsequently, nine studies, including five randomized controlled trials and four pre-post studies, were selected. There were 961 participants in the selected studies; PS dosage varied from 100 to 300 mg/d, and the experimental period ranged from 6 weeks to 6 months. Five out of the nine selected studies were assessed to have a 'low' risk of bias, whereas the other four studies were assessed to have 'some concerns' regarding the risk of bias. The results of the meta-analysis concluded that PS had a positive effect on the memory of older adults with cognitive decline. Thus, PS appears to improve age-associated cognitive decline, especially memory, with no adverse effects.

• 생명과학회지
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• 제12권4호
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• pp.460-463
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• 2002

Thyroglobulin과 반응하는 monoclonal antibody를 3클론(TN-1, TN-2 및 TN-3)을 확립하였다. 이들 중 1클론 (TN-2)은 thyroglobulin의 3차원적인 구조를 인식하면서 음전하를 띠는 자가항원의 일종인 phosphatidylserine과도 교차반응성을 나타내었다. 따라서 TN-2를 이용한 자가면역성 갑상선염의 진단 및 치료에의 적용효과가 기대된다.

• 대한핵의학회지
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• 제38권2호
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• pp.190-197
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• 2004

Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis is a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about $10^{-9}\;M$ for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with $^{99m}Tc$ by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

• 약학회지
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• 제27권4호
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• pp.249-256
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• 1983

When the reaction rate constant k of phospholipase D on liposome was measured by the ANS fluorometry, k of phospholipase D on DMPC liposome which was made of L-$\alpha$-PI, cholesterol and L-$\alpha$-PS decreased than that of phospholipase D on DMPC liposome with cholesterol or with PI and cholesterol. Optimal $Ca^{2+}$ concentration, the most important factor on effect of phospholipase D, also decreased to 1mM, as compared with 10mM and 60mM respectively when cholesterol and PI were added, and cholesterol only was added. The change of cholesterol Mol% had a great influence on k value of phospholipase D. But in case of addition of L-$\alpha$-PS to cholesterol, the influence was relatively diminished.

• Bulletin of the Korean Chemical Society
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• 제17권10호
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• pp.905-908
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• 1996

A substrate specificity of cabbage phospholipase D (PLD) was studied using the synthetic phospholipids having different head groups. The phospholipids were synthesized from phosphatidylcholine and appropriate bases by transphosphatidylation of PLD. The bases used were ethanolamine, serine, ethanol and γ-hydroxybutyric acid. The phosphatidic acid, the product of PLD, was separated in TLC and measured densitometrically. The kinetic parameters were estimated for each substrate and the effects of pH, SDS, Ca2+ and other metal ions were examined. Vmax values found were 3.75, 2.36, 5.59, 1.63, 2.30 nmol/min/μg protein for phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidylethanol, and phosphatidylburytic acid, respectively. These results indicate a broad specificity of cabbage PLD toward phospholipids with different head groups. Particularly phosphatidylserine was most easily hydrolyzed by PLD and its activity did not depend on Ca2+.

• BMB Reports
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• 제48권6호
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• pp.324-329
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• 2015

CopA3 is a homodimeric ${\alpha}$-helical peptide derived from coprisin which is a defensin-like antimicrobial peptide that was identified from the dung beetle, Copris tripartitus. CopA3 has been reported to have anticancer activity against leukemia cancer cells. In the present study, we investigated the anticancer activity of CopA3 in human gastric cancer cells. CopA3 reduced cell viability and it was cytotoxic to gastric cancer cells in the MTS and LDH release assay, respectively. CopA3 was shown to induce necrotic cell death of the gastric cancer cells by flow cytometric analysis and acridine orange/ethidium bromide staining. CopA3-induced cell death was mediated by specific interactions with phosphatidylserine, a membrane component of cancer cells. Taken together, these data indicated that CopA3 mainly caused necrosis of gastric cancer cells, probably through interactions with phosphatidylserine, which suggests the potential utility of CopA3 as a cancer therapeutic. [BMB Reports 2015; 48(6): 324-329]

• Biomolecules & Therapeutics
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• 제20권2호
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• pp.207-213
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• 2012

The present study examined the effects of krill-derived phosphatidylserine (Krill-PS) on the learning and memory function and the neural activity in rats with trimethyltin (TMT)-induced memory deficits. The rats were administered vehicle (medium-chain triglyceride: MCT) or Krill-PS (50, 100 mg/kg, p.o.) daily for 21 days. The cognitive improving efficacy of Krill-PS in TMT-induced amnesic rats was investigated by assessing the Morris water maze test and by performing choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and cAMP responsive element binding protein (CREB) immunohistochemistry. The rats with TMT injection showed impaired learning and memory of the tasks and treatment with Krill-PS produced a significant improvement of the escape latency to find the platform in the Morris water maze at the $2^{nd}$ and $4^{th}$ day compared to that of the MCT group (p<0.05). In the retention test, the Krill-PS+MCT groups showed increased time spent around the platform compared to that of the MCT group. Consistent with the behavioral data, Krill-PS 50+MCT group significantly alleviated the loss of acetylcholinergic neurons in the hippocampus and medial septum compared to that of the MCT group. Treatment with Krill-PS significantly increased the CREB positive neurons in the hippocampal CA1 area as compared to that of the MCT group. These results suggest that Krill-PS may be useful for improving the cognitive function via regulation of cholinergic marker enzyme activity and neural activity.