• Journal of Sericultural and Entomological Science
• /
• v.42 no.2
• /
• pp.120-125
• /
• 2000

This study was designed to investigate the effects of silk fibroin (Mw 500) powder (SFP) on lipofuscin, acetylcholine (ACh) and its related enzyme activities in brain of rats. Sprague-Dawley (SD) male rats (160$\pm$10 g) were fed basic diet (control group), and experimental diets (SFP-2.5 and SFp-5.0 groups) added 2.5 and 5.0 g/kg BW/day for 6 weeks. In case of liver membranes, lipofuscin (LF) levels resulted in a considerable decreases (11.5% and 13.8%, respectively) in SFP-2.5 and SFP-5.0 groups compared with control group. But in case of brain as the most sensitive organ, LF levels were remarkably inhibited about 18.3% and 21.7% in SFP-2.5 and SFP-5.0 groups compared with control group. Acetylcholine (ACh) levels were considerable decrease (3.0% and 9.2%, respectively) in brain membranes of SFP-2.5 and SFP-5.0 groups compared with control group. choine acetyltranferase (ChAT) activities as a synthesis enzyme of ACh, and acetylcholinesterase (AChE) activities as a hydrolysis enzyme resulted in a slight increases (2.4% and 3.0%, 4.6% and 6.3%, respectively), but significance difference between ChAT and AChE activities by SFP administration could be not obtained. Monoamine oxidase-B (MAO-B) activities were significantly inhibited (9.5% and 12.6%, respectively) in brain of SEP-2.5 and SFP-5.0 groups compared with control group. These results suggest that inhibiting effects of LF accumulation and MAO-B activity of silk fibroin(SFP) may play a pivotal role in protecting learning memory impairments by attenuating a various age-related changes for improvement of brain function.

• Biomolecules & Therapeutics
• /
• v.20 no.2
• /
• pp.152-157
• /
• 2012

Docosahexaenoic acid (DHA) is the major polyunsaturated fatty acid (PUFA) in the brain and a structural component of neuronal membranes. Changes in DHA content of neuronal membranes lead to functional changes in the activity of receptors and other proteins which might be associated with synaptic function. Accumulating evidence suggests the beneficial effects of dietary DHA supplementation on neurotransmission. This article reviews the beneficial effects of DHA on the brain; uptake, incorporation and release of DHA at synapses, effects of DHA on synapses, effects of DHA on neurotransmitters, DHA metabolites, and changes in DHA with age. Further studies to better understand the metabolome of DHA could result in more effective use of this molecule for treatment of neurodegenerative or neuropsychiatric diseases.

• Proceedings of the Korean Biophysical Society Conference
• /
• 1999.06a
• /
• pp.63-63
• /
• 1999

Large conductance $Ca^{2＋}$-activated $K^{＋}$ channels (Maxi-K channel) have been implicated in many important physiological processes such as co-ordination of membrane excitability in neurons. Modulation of these channels are archived by the activity of various protein kinases. The most widely studied example of Maxi-K channel regulation by protein phosphorylation has been obtained using plasma membranes from the rat brain incorporated into lipid bilayers.(omitted)

• BMB Reports
• /
• v.54 no.2
• /
• pp.118-123
• /
• 2021

The bacterial effector protein RavZ from a pathogen can impair autophagy in the host by delipidating the mammalian autophagy-related gene 8 (mATG8)-phosphatidylethanolamine (PE) on autophagic membranes. In RavZ, the membrane-targeting (MT) domain is an essential function. However, the molecular mechanism of this domain in regulating the intracellular localization of RavZ in cells is unclear. In this study, we found that the fusion of the green fluorescent protein (GFP) to the MT domain of RavZ (GFP-MT) resulted in localization primarily to the cytosol and nucleus, whereas the GFP-fused duplicated-MT domain (GFP-2xMT) localized to Rab5- or Rab7-positive endosomes. Similarly, GFP fusion to the catalytic domain (CA) of RavZ (GFP-CA) resulted in localization primarily to the cytosol and nucleus, even in autophagy-induced cells. However, by adding the MT domain to GFP-CA (GFP-CA-MT), the cooperation of MT and CA led to localization on the Rab5-positive endosomal membranes in a wortmannin-sensitive manner under nutrient-rich conditions, and to autophagic membranes in autophagy-induced cells. In autophagic membranes, GFP-CA-MT delipidated overexpressed or endogenous mATG8-PE. Furthermore, GFP-CA△α3-MT, an α3 helix deletion within the CA domain, failed to localize to the endosomal or autophagic membranes and could not delipidate overexpressed mATG8-PE. Thus, the CA or MT domain alone is insufficient for stable membrane localization in cells, but the cooperation of MT and CA leads to localization to the endosomal and autophagic membranes. In autophagic membranes, the CA domain can delipidate mATG8-PE without requiring substrate recognition mediated by LC3-interacting region (LIR) motifs.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.2
• /
• pp.117-125
• /
• 1997

The N-methyl-D-aspartate (NMDA) receptor-mediated glutamatergic neurotransmission is involved in synaptic plasticity, developmental processes, learning and memory and many neuropathological disorders including age-related diseases. In the present study, regulation of the NMDA receptor properties by various ligands was investigated using $[^3H]MK-801$ binding studies in the synaptic membranes of young and aged rat forebrains. The binding in the presence of glutamate and glycine increased dramatically with growth between 1 and 6 weeks old, and thereafter declined gradually with aging. Glutamate, glycine or spermine respectively increased the binding with growth. Glutamate maintained the binding during aging, while glycine or spermine significantly decreased the binding in the aged brain. The maximum stimulation by glycine varied depending on the ages of brains. Greater sensitivity to glycine was observed at 1 week and 3 months and the sensitivity was significantly reduced in the aged brain. In contrast, spermine showed similar stimulation patterns in young and aged rats. These results indicated that the functional properties of the NMDA receptor-ion channel complex in young and aged rat forebrains are differentially regulated by agonists, and the reduction of the receptor function with normal aging may be, in some degree, due to the reduction of the receptor sensitivity to glycine.

• Fisheries and Aquatic Sciences
• /
• v.2 no.2
• /
• pp.167-171
• /
• 1999

This study was designed to develop biomarkers of coastal pollution using biochemical indices of flounder (Paralichthys olivaceus) by changes in lactate dehydrogenase (LDH) activity in the serum and cholinesterase activities in brain membranes. For this purpose acetylcholiesterase (AChE) activity, butyrylcholinesterase (BChE) activity, LDH/AChE ratio and LDH/BChE ratio of cultured flounders at 5 different sites on the southern coast of Korea were compared to those of wild flounders caught in the Pohang, eastern coast of Korea as a control group. Relatively high LDH activities were measured in the serum of flounders cultured on the southern coast of Korea (0.101-0.145 unit) than those in the Pohang control group (0.093 unit). AChE activities were significantly low $(about\;10-20\%)$ in brain membranes of cultured flounders compared to those in the Pohang control group. The ratios of LDH/AChE and LDH/BChE were consistently higher $(136-178\%,\; 155-214\%)$ in cultured flounders than those of Pohang control group. Thus, we propose that the ratios of LDH/AChE and LDH/BChE in flounders could be applicable for the diagnosis of marine pollution.

• Journal of Life Science
• /
• v.10 no.6
• /
• pp.570-576
• /
• 2000

This study was designed to investigate the effects of mulberry (Morus alba L.) leaf extract (MLE) on oxygen radicals and their scavenger enzymes in brain membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10 g) were fed basic diet (control group), and experimental diets (MLE-100 and MLE-300 groups) added 100 and 300 mg/kg BW/day for 6 weeks. Hydroxyl radical (.OH) lecels resulted in significant decreases (13.4% and 21.1%, 12.0% and 13.4%, respectively) in brain mitochondria and microsome of MLE-100 and MLE-300 groups compared with control group. Superoxide radical ($O_2$) levels were significantly decreased about 12% in brain cytosol of MLE-300 group compared with control group. Lipid peroxide (LPO) levels were effectively inhibited (18.1% and 12.3%, respectively) in brain mitochondria and microsomes of MLE-300 groups compared with control group. Oxidized protein (OP) levels were significantly decreased (14.2%, and 10.9%, respectively) in brain mitochondria and microsomes of MLE-300 groups compared with control group. Mn-SOD activities in brain mitochondria were significantly increased (13.5% and 18.6%, respectively) in MLE-100 and MLE-300 groups, and Cu/Zn-SOD activities in brain cytosol were also effectively increased (about 17.7%) in MLE-300 groups compared with control group. GSHPx activities in brain cytosol were remarkably increased (17.2% and 23.9%, respectively) in MLE-100 and MLE-300 groups compared with control group. These results suggest that anti-aging effect of mulberry leaf extract (MLE) may play a pivotal role in attenuating a various age-related changes in brain.

• 대한치주과학회:학술대회논문집
• /
• 2005.11a
• /
• pp.223-223
• /
• 2005

• The Korean Journal of Pain
• /
• v.6 no.1
• /
• pp.74-82
• /
• 1993

신선한 소의 대뇌피질로부터 synaptosomal plasma membrane vesicles(SPMV)를 분리하고 이 SPMV로부터 추출한 총지질(cholesterol과 각종 인지질 함유)로서 제제한 인공세포막(SPMVTL)에서의 n-alkanols 침투 정도를 형광 probe를 이용한 형광 소광법을 통하여 검색하였다. n-alkanols는 SPMVTL 외부 단층(outer monolayer)의 표면에 주로 분포하되 그 탄소수에 비례하여 소수성 부위에 분포되는 양이 증가되는 경향을 나타내었다(1-decanol은 예외). Methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-hepatnol, 1-cotanol, 1-nonanol 및 1-decanol은 SPMVTL 외부 단층 표면(친수성 부위)에 분포되는 것이 소수성 부위에 분포되는 것에 비하여 각각 650, 288, 151.6, 69.5, 36.8, 11.9, 4.8, 1.6, 0.74, 2.1배가 된다는 것을 확인하였다. 1-decanol은 $C_{10}$인데도 불구하고 $C_8$인 1-octanol에 비하여 적은 양이 소수성 부위에 침투 분포되는 것이 확인되었다. 또한 n-alkanols는 저자등이 이미 보고한 SPMV에서의 경우보다도 본 연구에서의 SPMVTL의 경우가 현저하게 많은 양이 소수성 부위로 침투 분포된다는 것이 확인되었다.

• The Korean Journal of Pain
• /
• v.6 no.1
• /
• pp.67-73
• /
• 1993

소의 신선한 대뇌피질로부터 synaptosomal plasma membrane vesicles(SPMV)를 분리한 후 이 SPMV로부터 추출한 모든 인지질들로서 제제한 인공세포막(SPMVPL)에서의 n-alkanols 침투 정도를 형광 probe를 이용한 형광 소광법을 통하여 검색하였다. n-alkanols는 SPMVPL 외부 단층(outer monolayer)의 표면에 주로 분포하되 그 탄소수에 비례하여 소수성 부위에 분포되는 양이 증가되는 경향을 나타내었다. methanol, ethanol, 1-propano, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-nonanol 및 1-decanol은 SPMVPL 외부 단층의 표면(친수성 부위)에 분포되는 것이 소수성 부위에 분포되는 것에 비하여 각각 432.4, 208.9. 125.6, 88.2, 19.3, 7.9, 2.6, 1.0, 0.42, 1.36배가 되었다. 1-decanol은 $C_{10}$인데도 불구하고 $C_8$인 1-octanol에 비하여 적은 양이 소수성 부위에 침투 분포된다는 것이 확인되었다. n-alkanols의 침투에 대하여 저자등이 이미 보고한 바 있는 SPMV 및 SPMVTL(cholesterol+phospholipids)의 경우보다도 본 연구에서의 SPMVPL의 경우가 현저하게 많은 양이 소수성 부위로 침투 분포된다는 것도 확인되었다.