Differential glycosylatin 에 의한 dopamine beta - hydroxylase 의 multiple Forms 의 생산

황온유,조동협 ( On Yon Hwang,Tong Hyub Joh ) 생화학분자생물학회 1991 BMB Reports Vol.24 No.2

The enzyme dopamie beta-hydroxylase (DBH) catalyzes the conversion of dopamine to norepinephrine. DBH is a glycoprotein present in the catecholamine-containing vesicles and exists in both membrane-bound and soluble forms. We have previously shown that the soluble form of bovine adrenal medullary DBH have multiple forms of 75, 72 and 69 kDa as determined by SDS-PAGE We sought to investigate the relationship between glycosylation and the different molecular weight forms of bovine soluble DBH. Comparison of molecular weights of deglycosylated and glycosylated DBH revealed that after removal of the carbohydrate moieties, the triplet of 75, 72, and 69 kDa DBH became a single band of 66 kDa on SDS-PAGE, indicating that these multiple forms originated from differential glycosylation. This was further supported by the fact that DBH translated in vitro and thus without post translational processing mechanisms was a single band of 67 kDa, 1 kDa larger than the delycosylated mature DBH due to the presence of the cleavable N-terminal signal peptide. Comparison of the activites of the glycosylated and deglycosylated DBH revealed that carbohydrate moieties do not directly contribute to the catalytic activity of the mature DBH.

Dopamine β-Hydroxylase : Past, Present and Future

황온유 한국생화학분자생물학회 1990 생화학분자생물학회 소식 Vol.10 No.2

Dopamine β-hydroxylase (DBH) is one of the four enzymes in the catecholamine biosynthetic pathway and catalyzes the conversion of dopamine to norepinephrine. This paper reviews what is known about the distribution, localization, regulation, catalysis of this important neurotransmitter synthesizing enzyme. It further discusses the structure of DBH with emphasis on the structural complexity existing in multiple forms, and the recent cDNA cloning and primary structural analysis. The significance of the work on this enzyme done thus far is discussed and the direction of further research in this field proposed.

Role of Oxidative Stress in Parkinson’s Disease

황온유 한국뇌신경과학회 2013 Experimental Neurobiology Vol.22 No.1

Parkinson’s disease (PD) is a progressive neurodegenerative movement disorder associated with a selective loss of the dopamine(DA)rgic neurons in the substantia nigra pars compacta and the degeneration of projecting nerve fibers in the striatum. Because there is currently no therapy that delays the neurodegenerative process, modification of the disease course by neuroprotective therapy is an important unmet clinical need. Toward this end, understanding cellular mechanisms that render the nigral neurons particularly vulnerable have been a subject of intensive research. Increasing evidence suggests that oxidative stress plays a major role. The metabolism of DA itself contributes to oxidative stress, resulting in modification of intracellular macromolecules whose functions are important for cell survival. Mitochondrial dysfunction and the consequent increase in reactive oxygen species also trigger a sequence of events that leads to cell demise. In addition, activated microglia produce nitric oxide and superoxide during neuroinflammatory responses, and this is aggravated by the molecules released by damaged DAergic neurons such as α-synuclein, neuromelanin and matrix metalloproteinase-3. Ways to reduce oxidative stress therefore can provide a therapeutic strategy. NAD(P)H:quinone reductase (NQO1) and other antioxidant enzymes, whose gene expression are commonly under the regulation of the transcription factor Nrf2, can serve as target proteins utilized toward development of disease-modifying therapy for PD.

Dopamine β - Hydroxylase 연구의 과거 , 현재의 미래

황온유 ( On You Hwang ) 생화학분자생물학회 1992 생화학총설집 Vol.4 No.-

Regulation of Catecholamine Secretion and Synthesis by Histamine in Primary Cultured Bovine Chromaffin Cells

Hwang, Onyou,Na, Doesun,Song, Kyuyoung,Cho, Sung-Woo,Lee, Jae Dam 울산대학교 의과대학 1992 울산의대학술지 Vol.1 No.1

Histamine은 부신 수질 세포의 H₁수용체 활성화를 통한 phosphatidylinositide 가수 분해와 함께 catecholamine 유리를 촉진시킨다고 알려진 바 있다. 본 논문에서는 histamine의 세포 내 작용 기전을 밝히고자 histamine이 catecholamine 생합성 효소인 phenylenolamine N-methytransferase(PNMT)의 유전자 발현 및 catecholamine유리에 미치는 영향을 연구하였다. Histamine에 의한 catecholamine유리는 세포 외 calcium 유입에 의존적이었으나, 세포 내 저장 calcium과는 무관하였고, reserpine 및 탈분극에 의한 유리와 비슷한 수준이었다. Protein kinase C(PKC) 활성제 TPA에 의한 유리와 구별 될 수 없었으며, 그 억제제인 staurosporin에 의해 억제되었다. 또한, histamine은 PNMT mRNA를 증가시켰는데, 이 현상은 TPA에 의한 증가와 동일하며, dantrolene에 의한 차이는 없었으나, PKC 억제제인 sphingosine에 의해 억제되었다. 이상의 결과는 histamine이 chromaffin세포에서 PKC활성화를 통하여 catecholamine 유리 및 PNMT 유전자 발현의 증가시킴으로 catecholamine의 유리와 합성을 연결시킴을 시사하였다.

Mechanism and Thermodynamics of Interaction of Thymidylate Synthase with 5-Fluoro-2'-deoxyuridylate

Cho, Sung-Woo,Hwnag, Onyou,Song, Kyuyoung,Lee, Jae Dam,Na, Doesun 울산대학교 의과대학 1993 울산의대학술지 Vol.2 No.2

본 논문에서는 항암제로서 널리 쓰이는 5-fluoro-2'-deoxyuridylate(FdUMP)와 그 target이 되는 thymidylate synthase(TS)의 상호작용의 기전을 열역학적인 방법을 이용하여 연구하였다. 이들의 작용은 우선 비공유결합 상태의 복합체를 이룬뒤 다시 공유결합적 형태를 이루는 단계를 거치는데 이때의 전환속도는 25℃에서 0.6s??이었다. 또한 이때 비공유결합 상태의 복합체에서 CH₂H₄folate가 떨어져 나가는 유리 상수의 크기는 1uM이었다. 공유결합적 형태를 이루는데 쓰이는 열역학적 변수들은 각각 활성화 에너지 변화가 20kcal/mol, 자유 에너지 변화가 17.9kcal/mol, 엔탈피 변화가 19.3kcal/mol, 그리고 엔트로피 변화가 0.005kcal/mol/deg 였다. 비공유결합 상태의 복합체와 공유결합적 형태 사이의 평형상수는 2×10?이었으며 공유결합 상태의 복합체에서 CH?H?folate가 떨어져 나가는 최종 유리 상수의 크기는 10?M이었다. 이상의 결과 및 UV difference spectrum의 결과로 미루어 볼때 CH₂H₄folate 결합에너지의 일부가 5-iminium ion 중간물질의 형성에 쓰이고 있으며, 이러한 5-iminium ion 중간 물질의 형성 반응은 CH₂H₄folate의 N-10 위치에서의 general-acid catalysis및 비공유결합 상태의 TS-FdUMP-CH₂H₄folate 복합체내의 특정 부위의 변화에 의해서 촉진되어지는 것으로 추정된다.

살리실산 나트륨이 Guinea Pig 내이 외림프의 Unknown Compoung에 미치는 영향

김상윤,황온유,김혜진,추광철 울산대학교 의과대학 1993 울산의대학술지 Vol.2 No.2

There are some evidences that temporary hearing loss is induced by disturbance of cochlear microcirculation due to the inhibition of prostaglandin synthesis by salicylate, however, the mechanism of salicylate ototoxicity has been still under study. We previously suggested that the increase of unknown compound concentration in perilymph of guinea pig might be important for the mechanism of salicylate ototoxicity. So we tried to compare the time course of unknown compound concentration to salicylate concentration in perilymph. Sodium salicylate(460mg/kg) was injected intraperitoneally to guinea pig. Unknown compound concentration in perilymph was measured before the injection and 1 hour, 3 hours, 5 hours, 7 hours and 24 hours after injection, using HPLC-ECD. The time course of unknown compound concentration reveals maximum level at 5 hours and nearly control level at 24 hours, and this is similar to the change of salicylate concentration in perilymph. These data might be another evidence to our understanding of unknown compound-related salicylate ototoxicity.

양성 및 음성 증상 정신분열병 환자에서 혈장 Dopamine-P-hydroxylase 활성도에 관한 연구

김창윤,황온유,이철,한오수,박인호 대한신경정신의학회 1993 신경정신의학 Vol.32 No.1

The authors investigated the relationship between plasma D BH activities and positive/negative symptoms o f schizophrenia as proposed by Crow s two syndrome hypothesis and also the changes in the plasma DBH activities during 6 weeks o f antipsychotic treatment. The subjects were D SM -III-R schizophrenic or provisional schizophreniform patients(N =25) who were drug free at least for 4 weeks. Plasma DBH activities were measured with clinical symptom assessment repeatedly before(N =25) and during antipsychotic treatment(N二 15). Clinical symptoms were assessed with Positive and Negative Syndrome Scale (PANSS) and plasma DBH activites were assayed by modified Molinoff radioenzymatic method. The plasma DBH activities were found to be lower significantly in negative symptom schizophrenics compared with normal controls. This result suggests that plasma DBH activity may be a useful biological marker to delineate negative symptom subgroup of schizophrenia. It also supports the hypothesis that negative symptom subgroup of schizophrenia may be associated with decreased noradrenergic neurotransmission. The plasma D BH activities decreased after 6 weeks of antipsychotic treatment in positive symptom subgroup o f schizophrenia but not in negative symptom subgroup of schizophrenia. However the changes in plasma DBH activities after the antipsychotic treatment were not significantly different between positive and negative symptom subgroup. And also the changes in clinical symptoms did not correlate with the changes in the plasma DBH activities. Based on these findings, the changes in plasma DBH activities were speculated as not to reflect the changes in clinical symptoms but as the effects of antipsychotic drugs

Purification and Determination of in vitro and in vivo Activities of Recombinant Human Annexin Ⅰ

Kim,Chong-Kook,Cho,Sung-Woo,Hwang,On-you,Lee,Jae-Dam,Song,Kyu-young,Kim,Kyoung-Mi,Lee,Jong-Wook,Na,Doe-Sun 울산대학교 의과대학 1993 울산의대학술지 Vol.2 No.1

아넥신 Ⅰ은 칼슘의존적으로 인지질막에 결합하는 단백질군의 하나인 아넥신류에 속하며 상피성 성장 인자 수용체 키나제의 기질로 알려져있다. 그러나, 생체내 역할과 그 기전에 대하여는 밝혀지지 않고 있다. 아넥신Ⅰ의 생물학적 기능에 대한 자세한 연구를 하기위해 재조합 아넥신Ⅰ을 수용성 상태로 생산하였고, 대장균에서부터 EGTA추출한 후, DE-52 이온 교환, gel filtration, hydroxylapatite 칼럼을 통과시켜 대량으로 정제하였다. 정제된 아넥신Ⅰ은 시험관내에서 PLA를 억제하였고, 생체내에서 쥐 발바닥 부종에 대한 소염 효과를 나타내었다.

양성 및 음성 증상 정신분열병 환자에서 혈장 Dopamine-β-hydroxylase 활성도에 관한 연구

박인호,이철,황온유,한오수,김창윤 大韓神經精神醫學會 1993 신경정신의학 Vol.32 No.1

The authors investigated the relationship between plasma DBH activities and positive/negative symptoms of schizophrenia as proposed by Crow`s two syndrome hypothesis and also the changes in the plasma DBH activities during 6 weeks of antipsychotic treatment. The subjects were DSM-Ⅲ-R schizophrenic or provisional schzophreniform patients(N=25) who were drug free at least for 4 weeks. Plasma DBH activities were measured with clinical symptom assessment repeatedly (N=25) and during antipsychotic treatment(N=15). Clinical symptoms were assessed with Positive and Negative Syndrome Scale (PANSS) and plasma DBH activites were found to be lower significantly in negative symptom schizophrenics compared with normal controls. This result suggests that plasma DBH activity may be a useful biological marker to delineate negative symptom subgroup of schizophrenia. It also supports the hypothesis that negative symptom subgroup of schizophrenia may be associated with decreased noradrenergic neurotransmission. The plasma DBH activities decreased after 6 weeks of antipsychotic treatment in positive symptom subgroup of schizophrenia but not in negative symptom subgroup of schizophrenia. However the changes in plasma DBH activities after the antipsychotic treatment were not significantly different between positive and negative symptom subgroup. And also the changes in clinical symptoms did not correlate with the changes in the plasma DBH activities. Based on these findings, the changes in plasma DBH activities were speculated as not to reflect the changes in clinical symptoms but as the effects of antipsychotic drugs.