• 한국식품영양과학회지
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• 제22권4호
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• pp.458-464
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• 1993

전보에 이어, 정제한 혈합육어 trypsin에 대하여 효소적 성질 및 열 역학적 성질에 관하여 비교 검토한 내용을 요약하면 다음과 같다. 이들 혈합육어 trypsin은 BA-p-NA와 SP-p-NA 같은 amide기질 중 BA-p-NA기질만에 대하여, 그리고 ATEE, BAEE, BTEE 및 TAME 등의 ester 기질 중에서는 BAEE와 TAME에 대하여만 현저한 활성을 보였다. 이들 효소는 antipain, leupeptin, DFP, TLCK, SBTI 등 화학약제와 금속이온 Cu$^{2＋}$ 및 Hg$^{2＋}$에 의하여서는 그 활성이 현저히 저해를 받았으나, $Mg^{2＋}$에 의하여서는 부활하였다. 이 효소들은 모두 5$0^{\circ}C$ 이상의 온도에서는 불안정하였으며, 날개다랭이의 trypsin이 온도 변화에 대하여 가장 안정하였다. 그리고, 활성화에너지는 멸치 trypsin이 13.91㎉/mo1e, 고등어 trypsin A는 11.61㎉/ mole, 고등어 trypsin B는 8.43㎉/mo1e, 황다랭이 trypsin은 4.35㎉/mole, 그리고 날개다랭이 trypsin은 3.76㎉/mole 이었다.

• The Korean Journal of Physiology and Pharmacology
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• 제14권1호
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• pp.37-43
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• 2010

The serine/threonine kinase Akt has been shown to play a role of multiple cellular signaling pathways and act as a transducer of many functions initiated by growth factor receptors that activate phosphatidylinositol 3-kinase (PI3K). It has been reported that phosphorylated Akt activates eNDS resulting in the production of NO and that NO stimulates soluble guanylate cyclase (sGC), which results in accumulation of cGMP and subsequent activation of the protein kinase G (PKG). It has been also reported that PKG activates PI3K/Akt signaling. Therefore, it is possible that PI3K, Akt, eNOS, sGC, and PKG form a loop to exert enhanced and sustained activation of Akt. However, the existence of this loop in eNOS-expressing cells, such as endothelial cells or astrocytes, has not been reported. Thus, we examined a possibility that Akt phosphorylation might be enhanced via eNOS/sGC/PKG/PI3K pathway in astrocytes in vivo and in vitro. Phosphorylation of Akt was detected in astrocytes after KA treatment and was maintained up to 72 h in mouse hippocampus. 2 weeks after KA treatment, astrocytic Akt phosphorylation was normalized to control. The inhibition of eNOS, sGC, and PKG significantly decreased Akt and eNDS phosphorylation induced by KA in astrocytes. In contrast, the decreased phosphorylation of Akt and eNDS by eNDS inhibition was significantly reversed with PKG activation. The above findings in mouse hippocampus were also observed in primary astrocytes. These data suggest that Akt/eNOS/sGC/PKG/PI3K pathway may constitute a loop, resulting in enhanced and sustained Akt activation in astrocytes.

• 미생물학회지
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• 제40권2호
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• pp.87-93
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• 2004

세포질과 핵단백질의 serine과 threonine 잔기에 O-linked N-acetyl-$\beta$-glucosamine (O-GlcNAc)의 첨가는고등 진핵 세포에서 흔히 일어나는 번역 후 단백질의 변형 중 하나로서 단백질의 인산화와 유사한 세포 내 신호전달에 관여하는 것으로 보인다. O-GlcNAc의 첨가와 제거는 O-GlcNAc transferase (OGT)와 O-linked N-acetyl-$\beta$-D-glucos-aminidase (O-GlcNAcase) 효소에 의해 각각 촉매된다. 두가지 종류의 사람 유래 O-GlcNAcase 유전자(O-GlcNAcase, v-O-GlcNAcase)를cloning하고 세 가지의 융합단백질로 대장균에서 생산을 시도하였다. O-GlcNAcase의 기질 유사체 인 ${\rho}$-nitrophenyl-N-acetyl-$\beta$-D-g1ucosaminide (${\rho}$NP-$\beta$-D-GlcNAc)를 기질로 사용하여 효소활성을 측정 한 결과 v-O-GlcNAcase는 활성을 나타내지 않았다. 여러 종류의 amino sugar 기질 유사체를 사용하여 O-GlcNAcase의 활성을 측정하였으나 오직 ${\rho}$NP-$\beta$-D-GlcNAc만이 활성을 보였다. Blast검색으로 분석한 결과 아미노 말단의 hyaluronidase-like domain (hyaluronidase-유사 영역)과 카르복시 말단의 N-acetyltransferase 영역 두 곳의 conserved domains 존재하였다. 효소촉매에 중요한 영역을 밝히기 위해 여러 deletion mutants(결손 변이체)를 제작한 후 효소활성을 측정하고 Western blot으로 분석하였다. Hyaluronidas-유사 영역, 유전자 내부와 N-acetyltransferase 영역을 제거할 경우 효소활성이 사라졌으나 아미노 말단의 55개 아미노산과 카르복시 말단의 truncation은 활성을 일부분 유지하였다. 위의 사실에 기초하여 hyaluronidas-유사 영역은 효소활성에 중요하고 카르복시 말단의 N-acetyltransferase 영역은 조절기능으로 작용하는 것으로 추정된다.

• Biomolecules & Therapeutics
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• 제15권1호
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• pp.16-26
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• 2007

Tissue plasminogen activator (tPA) is a serine protease catalyzing the proteolytic conversion of plasminogen into plasmin, which is involved in thrombolysis. During last two decades, the role of tPA in brain physiology and pathology has been extensively investigated. tPA is expressed in brain regions such as cortex, hippocampus, amygdala and cerebellum, and major neural cell types such as neuron, astrocyte, microglia and endothelial cells express tPA in basal status. After strong neural stimulation such as seizure, tPA behaves as an immediate early gene increasing the expression level within an hour. Neural activity and/or postsynaptic stimulation increased the release of tPA from axonal terminal and presumably from dendritic compartment. Neuronal tPA regulates plastic changes in neuronal function and structure mediating key neurologic processes such as visual cortex plasticity, seizure spreading, cerebellar motor learning, long term potentiation and addictive or withdrawal behavior after morphine discontinuance. In addition to these physiological roles, tPA mediates excitotoxicity leading to the neurodegeneration in several pathological conditions including ischemic stroke. Increasing amount of evidence also suggest the role of tPA in neurodegenerative diseases such as Alzheimer's disease and multiple sclerosis even though beneficial effects was also reported in case of Alzheimer's disease based on the observation of tPA-induced degradation of $A{\beta}$ aggregates. Target proteins of tPA action include extracellular matrix protein laminin, proteoglycans and NMDA receptor. In addition, several receptors (or binding partners) for tPA has been reported such as low-density lipoprotein receptor-related protein (LRP) and annexin II, even though intracellular signaling mechanism underlying tPA action is not clear yet. Interestingly, the action of tPA comprises both proteolytic and non-proteolytic mechanism. In case of microglial activation, tPA showed non-proteolytic cytokine-like function. The search for exact target proteins and receptor molecules for tPA along with the identification of the mechanism regulating tPA expression and release in the nervous system will enable us to better understand several key neurological processes like teaming and memory as well as to obtain therapeutic tools against neurodegenerative diseases.

• 한국잠사곤충학회지
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• 제53권1호
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• pp.6-11
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• 2015

국내에서 생산한 천잠 누에고치의 일반 특성을 고찰한 결과 국내산 천잠 누에고치는 연두색 고치를 지으며, 층상구조를 가지고 있었다. 천잠 누에고치는 외피는 연두색이었고 내피는 흰색을 나타내어 천잠 누에고치의 색상을 나타내는 색소 성분은 외피에 존재하였다. 천잠 누에고치는 고치층의 무게는 0.528 g, 견층두께는 0.424 mm로 측정되었다. 천잠 누에고치를 구성하는 주요 아미노산은 알라닌, 글리신, 세린, 아스파르트산, 티로산, 아르기닌 순으로 나타났으며, X-선 회절분석 결과 $2{\theta}=16.8^{\circ}$, $20.4^{\circ}$ 부근에서 강한 회절 피크와 $2{\theta}=15.0^{\circ}$, $24.3^{\circ}$, $30.0^{\circ}$ 부근에서 날카로운 회절 피크를 나타내었다. 천잠 누에고치는 폭이 $20{\mu}m$ 정도인 섬유가 적층된 구조를 가지고 있으며, 고치의 안쪽과 바깥쪽에 흰색 결정을 가지고 있었다. 천잠 누에고치의 최대 열분해 온도는 $370^{\circ}C$ 부근이었다. 이러한 천잠 누에고치에 대한 연구 결과는 향후 천잠 누에고치를 이용한 소재 개발의 기초 자료로 활용될 수 있을 것으로 기대한다.

• 한국식품과학회지
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• 제31권1호
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• pp.171-175
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• 1999

우리나라 전통고유음료인 숭늉의 산업적 가공공정 확립의 일환으로 숭늉제조에 적합한 볶음 공정을 확립하기 위하여 볶음 온도 150, 180, 200, $220^{\circ}C$에서 10, 20, 30분간 각각 볶음 처리하여 이들 각 시료의 이화학적 특성을 조사하였다. 색깔의 변화에서 볶음 온도가 높을수록 볶음 시간이 길수록 명도와 황색도는 감소하였으나 색차는 증가하였다. 볶음온도 $150^{\circ}C$에서 $200^{\circ}C$까지는 수분흡수지수가 약간 증가하는 경향이 있었으나 $220^{\circ}C$에서는 크게 감소하였다. 수분용해도지수는 볶음 온도가 높을수록 볶음 시간이 길수록 증가하였다. 고형분 함량은 볶음 온도가 높아짐에 따라 현저히 증가하였고 같은 온도에 있어서도 볶음 시간이 길수록 높은 값을 보였다. 한편 침전물 생성량과 탁도는 볶음 시간이 길수록 볶음 온도가 높을수록 감소하였다. 환원당의 함량은 볶음 온도 $180^{\circ}C$에서는 볶음 시간이 길수록 감소하여 20분간 볶음 처리시는 10분간 볶음처리시의 29%에 지나지 않았다. 그러나 볶음 온도 150, $200^{\circ}C$에서는 볶음 시간이 길수록 환원당량이 증가하였으며 특히 $220^{\circ}C$에서 20분 또는 30분간 볶음 처리한 경우는 현저히 높은 값을 보였다. 또한 아미노산 함량의 변화를 조사한 결과 볶음 온도가 높아짐에 따라 총 아미노산의 함량은 감소하여 $200^{\circ}C$, 30분간 볶음처리시는 $150^{\circ}C$, 30분 볶음처리시의 약 57% 정도였다. 아미노산의 종류별로 보면 볶음 온도가 높아짐에 따라 각종 아미노산이 모두 감소하였으며 그 중에서도 threonine, serine, lysine, cystine의 함량이 크게 감소하였다.

• Journal of Microbiology and Biotechnology
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• 제8권2호
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• pp.158-164
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• 1998

Crystal structural analyses of the API-TLCK complex revealed that the ${\epsilon}$-amino group (NZ) of the lysyl part of TLCK forms hydrogen bonds with OD1 of $Asp^225$ which is a substrate specificity determinant of API, OG of $Ser^214$, O of $Ser^214$, OG1 of $Thr^189$, and O of $Thr^189$ l89/. The ${\beta}$-carboxyl oxygen of $Asp^225$ forms hydrogen bonds with the NE1 of $Trp^182$. From these observations, it is thought that besides $Asp^225$, $Thr^189$, $Ser^214$, and $Trp^182$ may also contribute to the steric specificity for lysine and high proteolytic activity of API. The side-chain hydroxyl groups of $Thr^189$ and $Ser^214$ were removed to elucidate the role of these hydrogen bonds in the $S_1$-pocket. The $k_{cat}$/$K_m$ of T189V, S214A, and T189V.S214A were decreased to 1/4, 1/3, and 1/46, respectively, of the value for native API. The decreased activities were mainly due to the increase of $K_m$. The CD and fluoroscence spectra of the three mutants were similar to those of wild-type API. With regards to the kinetic parameters ($K_i\;and\;k_2$) of mutants for the reaction involving TLCK and DFP, $k_2$decreased by increase of $K_1$ only. These results suggest that the decreased catalytic activity of these mutants is caused by the partial loss of the hydrogen bond network in the $S_1$-pocket. On the other hand, the similarity of enzymatic properties between W182F and the native enzyme suggests that the hydrogen bond between OD2 of $Asp^225$ and NE1 of $Trp^182$ is not directly related to the reaction of $Asp^225$ with the substrate.

• Journal of Microbiology and Biotechnology
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• 제21권4호
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• pp.366-373
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• 2011

We characterized the proteomes of murine N2a cells following infection with three rabies virus (RV) strains, characterized by distinct virulence phenotypes (i.e., virulent BD06, fixed CVS-11, and attenuated SRV9 strains), and identified 35 changes to protein expression using two-dimensional gel electrophoresis in whole-cell lysates. The annotated functions of these proteins are involved in various cytoskeletal, signal transduction, stress response, and metabolic processes. Specifically, a-enolase, prx-4, vimentin, cytokine-induced apoptosis inhibitor 1 (CIAPIN1) and prx-6 were significantly up-regulated, whereas Trx like-1 and galectin-1 were down-regulated following infection of N2a cells with all three rabies virus strains. However, comparing expressions of all 35 proteins affected between BD06-, CVS-11-, and SRV9-infected cells, specific changes in expression were also observed. The up-regulation of vimentin, CIAPIN1, prx-4, and 14-3-3 ${\theta}/{\delta}$, and down-regulation of NDPK-B and HSP-1 with CVS and SRV9 infection were ${\geq}2$ times greater than with BD06. Meanwhile, Zfp12 protein, splicing factor, and arginine/serine-rich 1 were unaltered in the cells infected with BD06 and CVS-11, but were up-regulated in the group infected with SRV9. The proteomic alterations described here may suggest that these changes to protein expression correlate with the rabies virus' adaptability and virulence in N2a cells, and hence provides new clues as to the response of N2a host cells to rabies virus infections, and may also aid in uncovering new pathways in these cells that are involved in rabies infections. Further characterization of the functions of the affected proteins may contribute to our understanding of the mechanisms of RV infection and pathogenesis.

• Reproductive and Developmental Biology
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• 제28권3호
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• pp.187-190
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• 2004

PKC는 그들의 cofactor-requirments에 따라 cPKC, nPKC 그리고 aPKC, 3그룹으로 나어진다. 마우스 난 성숙과정에 있어서 cPKC 및 nPKC의 activators인 PMA의 영향에 대한 많은 결과가 보고되었다. 그러나 각각의 그룹에 대한 차별화된 영향에 대하여는 밝혀져 있지 않다. Mezerein의 analog인 thymeleatoxin은 cPKC의 특이적인 activator로 보고되어져 있다. 본 연구에서는 specific cPKC activator인 thymeleatoxin의 마우스 난 성숙과정에의 영향을 제1감수분열 재개 능(germinal vesicle break down, GVBD)과 제1 극체 형성 능(1st polar body extrusion)을 조사하여 cPKC및 nPKC activator인 PMA와 비교 검토하였다. 그 결과 GVBD IC50는 thymeleatoxin에서 ～400nM, PMA에서는 ～50nM이었으며, 제1극체 방출의 IC50는 thymeleatoxin에서 ～200nM, PMA에서는 ～20nM이었다. 이들 결과는 Thymeleatoxin의 GVBD나 1st polar body extrusion 저해효과가 PMA에 비하여 1/8～1/10인 것으로 나타났다. 이들 결과는 GVBD나 제1극체 형성을 포함하는 난 성숙과정에서 cPKC보다 상대적으로 nPKC의 관여가 깊음을 보여 준다.

• Reproductive and Developmental Biology
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• 제35권3호
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• pp.273-280
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• 2011

It was conducted the experiment, divided into three groups as normal, poor and polycystic ovary syndrome, to detect the change of protein patterns in follicular fluid on ovarian response following controlled ovarian hyperstimulation for human IVF outcome. In the normal group, it was confirmed reproducible 57 spots in the detected total 81 spots. Then 1 spot was not found in the other groups. In the poor responder group, it was found reproducible 53 spots in the detected total 98 spots. 6 spots were down-regulation and 7 spots were up-regulation comparable with normal group. There were not 5 spots in poor responder group comparable with other groups. In the polycystic ovary syndrome group, it was expressed reproducible 53 spots in the detected total 80 spots and 3 spots were just expressed in this group. However, 4 spots were not found in polycystic ovary syndrome. 9 spots were up-regulation comparable with normal group. Significant up and down-regulation spots among the each groups were identified. The results were a cytosolic carboxypeptidase, a signal-induced proliferation-associated protein 1, a ceruloplasmin, a keratin(type II cytoskeletal 1), a polypeptide N-acetylgalactosantinyltransferase 2, a serine/threonine-protein phosphatase 4 regulatory subunit 4. It was identified that 8 spots, 6 kinds of protein are corresponded with NCBInr database research, but 10 spots were failed in the identification. In conclusion, it has been confirmed change and expression of protein on the ovarian response following COH of human.