NMR Signal Assignments of Human Adenylate Kinase 1 (hAK1) and its R138A Mutant (hAK1R138A)

김길훈,장환봉,원호식 한국자기공명학회 2016 Journal of the Korean Magnetic Resonance Society Vol.20 No.2

Adenylate kinase (AK) enzyme which acts as the catalyst of reversible high energy phosphorylation reaction between ATP and AMP which associate with energetic metabolism and nucleic acid synthesis and signal transmission. This enzyme has three distinct domains: Core, AMP binding domain (AMPbd) and Lid domain (LID). The primary role of AMPbd and LID is associated with conformational changes due to flexibility of two domains. Three dimensional structure of human AK1 has not been confirmed and various mutation experiments have been done to determine the active sites. In this study, AK1R138A which is changed arginine[138] of LID domain with alanine[138] was made and conducted with NMR experiments, backbone dynamics analysis and mo-lecular docking dynamic simulation to find the cause of structural change and substrate binding site. Synthetic human muscle type adenylate kinase 1 (hAK1) and its mutant (AK1R138A) were re-combinded with E. coli and expressed in M9 cell. Expressed proteins were purified and finally gained at 0.520 mM hAK1 and 0.252 mM AK1R138A. Multinuclear multidimensional NMR experiments including HNCA, HN(CO)CA, were conducted for amino acid sequence analysis and signal assignments of 1H-15N HSQC spectrum. Our chemical shift perturbation data is shown LID domain residues and around alanine[138] and per-turbation value(0.22ppm) of valine[179] is consid-ered as inter-communication effect with LID domain and the structural change between hAK1 and AK1R138A.

빈랑자 (Arecae Semen)로부터 Urease 억제 활성 물질의 분리

임문정,류제만,장환봉,노양국,오성준,이현용 한국생약학회 2005 생약학회지 Vol.36 No.1

Urease plays an important role in the urea metabolism and the effect of urease activity on human and environment is enormous. For instance, urease acts as a virulence factor of the urinary and gastrointestinal tracts infections in human and animal, being involved in kidney stone formation, catheter encrusatation, pyelonephritis, ammonia encephalopathy, hepatic coma, and urinary tract infections. Widespread urease activity in soil induces a plant damage due to ammonia toxicity and pH increase. Therefore, urease activity regulation through urease inhibitors would lead to an enhanced efficiency of urea nitrogen uptake in plants and to the improved therapeutic strategies for ureolytic bacterial infections. To search for new inhibitory compounds on urease activity from herbs, MeOH extracts of herbs were screened. Among of them, the MeOH extracts of Areca catechu exhibited an excellent inhibitory effect on urease activity. Two compounds were isolated from the ethyl acetate fraction by the activity guided fractionation. Their chemical structures were identified as (+)-catechin(compound I) and allantoin(compound II) by spectroscopic evidence, respectively. Compound I showed a stronger inhibitory effect on urease activity than compound II.

Studies of Square Pyramidal Nickel(Ⅱ)-Containing Coenzyme F430 Model Complexes

Won, Hoshik,Chun, Hyungphil,Kwak, Bunghun,Chang, Hwanbong,Park, Seunghee 漢陽大學校 基礎科學硏究所 1995 基礎科學論文集 Vol.14 No.-

보조효소 F430은 사각평면의 중앙에 Ni(Ⅱ)원자가 결합하여 있는 tetrapyrrole의 corphin 거대고리 분자이다. 최근 구조연구에 의하면 corphin은 보조효소 B₂에서의 corrin 거대고리와 유사하게 부분적으로 이중결합의 연결되어 있으며 거대고리 전체가 굽혀지고 주름이 잡혀있는 것으로 보고되고 있다. F430의 촉매메카니즘에 관여하는 corphin고리의 역활을 이해하기 위해, 모델착물 Ni((DO)(DOH)pn]I 을 합성하였고 Ni(Ⅱ)[(DO)(DOBF₂)pn]I와 구조적인 비교를 시행하였다. 두착물의 중요한 차이점은 적도방향 리간드가 분자평면으로 부터 다른 굽힘각(α)을 준다는 것이다. Ni((DO)(DOH)pn)I은 평면으로부터 11.6˚의 굽힘각을 나타내고, 반면에 Ni((DO)(DOBF₂)pn)I의 굽힘각은 19.0˚을 나타낸다. 두 화합물에서 결합은 Ni원자는 각각의 diimino 형태들(최대 π-orbital overlap을 유지하기 위해서)과 동일 평면상에 남기위해 수직방향 리간드와 거리가 멀게 위치한다. I방향으로 Ni원자가 4개의 질소평면으로부터 Ni((DO)(DOH)pn)I에서는 0.188Å 만큼 떨어져있고, Ni((DO)(DOBF₂)pn)I에서는 0.23Å 떨어져있다. 또한 Ni((DO)(DOH)pn)I에서 얻어진 긴 Ni-I 결합거리는(DO)(DOH)pn 리간드가 (DO)(DOBF₂)pn보다 더욱 강한 강성(rigidity)을 갖고 있음을 나타낸다. Coenzyme F430 consists of a tetrapyrrole corphin macrocycle with a centrally bound, square planar Ni(Ⅱ) atom. Recent structural studies exhibit that the corphin is not fully conjugated and is thus able to bend or ruffle as in the corrin macrocycle in coenzyme B12. In order to increase the functions of corphin ring in the mechanistic details of F430 - dependent catalysis, model complex Ni [(DO)(DOH)pn] I was synthesized and structural comparison was made with Ni((DO)(DOBF₂)pn) I. Significant difference between complexes was the angle of deviation from planarity of the equatorial ligand (bending angle α). Ni((DO)(DOH)pn) I exhibits deviation from planarity of 11.6˚whereas deviation in Ni((DO)(DOBF₂)pn) I is 19˚. In both compounds, bending is away from the axial ligands such that the Ni atom remains coplanar with each of the diimino moieties(to maintain maximum π-orbital overalp), and is displaced from the 4-N plane towards I by 0.188Å in Ni((DO)(DOH)pn) I and 0.23Å in Ni((DO)(DOBF₂)pn) I. The very long Ni - I bond in Ni((DO)(DOH)pn) I is thus a consequence of the greater rigidity of the (DO)(DOH)pn ligand compared to the (DO)(DOBF₂)pn ligand.

DW2007 Ameliorates Colitis and Rheumatoid Arthritis in Mice by Correcting Th17/Treg Imbalance and Inhibiting NF-κB Activation

임수민,이상윤,정진주,최현식,장환봉,김동현 한국응용약물학회 2016 Biomolecules & Therapeutics(구 응용약물학회지) Vol.24 No.6

In the previous study, the rhizome mixture of Anemarrhena asphodeloides and Coptis chinensis (DW2007), improved TNBS-, oxazolone-, or DSS-induced colitis in mice by regulating macrophage activation. Therefore, to understand the effect of DW2007 on the T cell differentiation involved in the adaptive immunity, we measured its effect on both Th17 and Treg cell differentiation in splenocytes, in the lamina propria of mice with DSS-induced colitis (DIC), and in the spleens of mice with collagen-induced arthritis (CIA). Results showed that DW2007 potently inhibited the differentiation of splenocytes into Th17 cells, but increased Treg cell differentiation in vitro. In the colon of wild type and TLR4-/- mice with DIC, DW2007 potently suppressed DSS-induced colon shortening and myeloperoxidase activity. DW2007 also suppressed collagen-induced paw thickening, clinical index, and myeloperoxidase activity in CIA mice. Overall, DW2007 potently suppressed Th17 cell differentiation in mice with CIA and DIC, but increased Treg cell differentiation. Moreover, DW2007 strongly inhibited the expression of TNF-α and IL-1β, as well as the activation of NF-κB. Based on these findings, DW2007 may ameliorate inflammatory diseases by regulating the innate immunity via the inhibition of macrophage activation and the adaptive immunity via the correction of disturbed Th17/Treg cells.

스마트팜 재배 병풀의 triterpenes 정량 및 각질형성세포 활성화 효과

박진홍,조성민,이다희,박영민,장환봉,강태진,이기만 한국식품저장유통학회 2023 한국식품저장유통학회지 Vol.30 No.3

This study aimed to compare the bioactive compounds in Centella asiatica (C. asiatica) cultivated in a smart farm and a field and their effects on human keratinocyte cells. C. asiatica was collected in Jeju-do, Korea, and cultured in a smart farm and a field. The main bioactive compounds in the two differentially cultured C. asiatica were identified, and their activation in keratinocytes were assessed. Amplification and sequencing of the internal transcribed spacer (ITS) DNA in the nucleus and psbA-H DNA in the chloroplast were performed for species analysis. A comparison of DNA of plants reported in the NCBI GenBank was performed. The ITS DNA and psbA-H DNA sequences of C. asiatica cultivated in a smart farm and a field were consistent with No. MH768338.1 and No. JQ425422.1, respectively. Analysis of the triterpenes was performed using high performance liquid chromatography (HPLC) and as a result, C. asiatica cultured in a smart farm had more triterpenes than those cultured in a field. The effects of C. asiatica grown in a smart farm on cell proliferation and scratch recovery in HaCaT cells were greater than those grown in a field. These results suggest that C. asiatica cultivated in a smart farm can be effectively utilized as a health functional food.