Judul: Uji Kestabilan Ikatan antara Protein Plasmepsin II dengan Ligan Alami sebagai Kandidat Obat Antimalaria
Abstrak: Malaria merupakan penyakit menular yang disebabkan oleh protozoa bernama Plasmodium. Plasmodium falciparum adalah spesies yang paling mematikan. Setiap tahunnya terdapat 500 juta orang menderita malaria dan 1-3 juta orang meninggal dunia akibat penyakit ini. Protein plasmepsin II bekerja di bagian vakuola makanan dari Plasmodium falciparum dan berfungsi memecah hemoglobin sel inang. Plasmepsin II adalah target obat yang efektif untuk pengobatan malaria. Oleh karena itu dibutuhkan kandidat obat baru untuk menghambat aktivitas Plasmepsin II. Metode yang digunakan dalam menguji 50 ligan alami adalah simulasi penambatan molekul dan simulasi dinamika molekul. Stabilitas interaksi antara protein Plasmepsin II dengan ligan uji Isostrychnopentamine ditunjukkan dengan perubahan energi bebas gibbs, RMSD, RMSF serta energi van der Waals yang fluktuatifnya stabil. Hal tersebut menunjukkan bahwa ligan uji Isostrychnopentamine terbukti dapat dijadikan kandidat kuat sebagai obat antimalaria yang baru.
Keyword: Plasmodium falciparum, plasmepsin II, simulasi penambatan molekul, simulasi dinamika molekul

Judul: Virtual Screening of Active Compounds of Medicinal Plants with Antimalarial Potential: Molecular Docking to PfENR Proteins
Abstrak: Malaria adalah penyakit menular global yang menyerang ratusan juta orang setiap tahun. Penyakit ini disebabkan oleh parasit (protozoa) dan ditularkan melalui nyamuk Anopheles. Terdapat enam spesies plasmodium yang menularkan malaria pada manusia, dan yang paling banyak menyebabkan kematian adalah Plasmodium falciparum. Pengembangan obat antimalaria telah dilakukan sejak lama. Namun Plasmodium falciparum memiliki kemampuan untuk beradapatasi terhadap obat sehingga menyebabkan resistensi obat yang ada. Oleh karena itu perlu dilakukan kombinasi pencarian obat dan target baru. Penelitian ini melakukan penambatan molekuler (molecular docking) terhadap 161 ligan tanaman dengan reseptor berupa protein Plasmodium falciparum Enyl-Acyl Carrier Protein Reductase (PfENR). ENR adalah enzim yang berperan dalam biosintesis asam lemak lemak tipe II yang merupakan komponen utama dalam dinding sel mikroba. Dari 161 ligan yang ditambatkan, diperoleh 18 ligan alami dengan nilai energi afinitas yang paling negatif dari rentang -10,00 kkal/mol hingga -12,56 kkal/mol dan dinyatakan lulus uji Lipinski. Interaksi antara liganprotein juga dianalisis berupa interaksi ikatan hidrogen dan hidrofobik, dimana interaksi ini berpengaruh terhadap nilai afinitas pengikatan dan memberi informasi terkait sisi aktif protein.
Keyword: energy afinitas ikatan, interaksi ligan-protein, penambatan molekul, Plasmodium falciparum

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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