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"Enzyme catalysis is a topic of fundamental importance in organic, bio-organic and medicinal chemistry. This new edition of a very popular textbook provides a concise introduction to the underlying principles and mechanisms of enzyme and coenzyme action from a chemical perspective.Whilst retaining the overall structure of the first edition, preliminary chapters describe the basic principles of enzyme structure and catalysis moving through to detailed discussions of the major classes of enzyme processes in the later chapters, the book has been thoroughly updated to include information on the most recent advances in our understanding of enzyme action. A major feature of the second edition is the inclusion of two-colour figures of the active sites of enzymes discussed in the text, in order to illustrate the interplay between enzyme structure and function. Problems, with outline answers, at the end of each chapter give the student the chance to the check their understanding of the material."

"Pada penelitian ini dilakukan ekstraksi biji beligo (Benincasa hispida) dengan metode ekstraksi soxhlet yang menghasilkan rendemen sebesar 27,21%. Hasil pengujian daya inhibisi ekstrak biji beligo pada berbagai fraksi yang diperoleh yaitu : fraksi etanol, etil asetat, n-butanol dan air terhadap aktivitas α-glukosidase menunjukkan efek inhibisi yang cenderung meningkat seiring dengan meningkatnya konsentrasi dari masing-masing fraksi. Daya inhibisi terbesar terdapat pada ekstrak biji beligo fraksi air dengan konsentrasi 62,5 ppm adalah sebesar 26,6%. Pengujian toksisitas akut dilakukan untuk mengetahui sifat toksisitas ekstrak biji beligo pada fraksi yang menghasilkan inhibisi aktivitas α-glukosidase terbesar terhadap Daphnia magna dan Artemia salina. Dari pengujian toksisitas akut terhadap Daphnia magna didapatkan nilai sebesar 818,7 ppm. Dari hasil pengujian toksisitas akut terhadap Artemia salina didapatkan nilai sebesar 3698,0 ppm.

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In this study, beligo (Benincasa hispida) seeds extraction was conducted with sohxlet extraction method which producing crude extracts amounted to 27,21%. The test results of inhibition power of beligo seeds extract on various fractions were obtained, which is the fraction of ethanol, ethyl acetate, n-butanol, and water towards activity α-glucosidase reveal that the inhibition effect is increasing as well as concentrations increase of each fraction. The greatest inhibition effect on beligo seeds extract fraction of water with concentration of 62,5 ppm is 26,6%. Acute toxicity testing conducted to determine the toxicity of beligo seeds extract in the fraction that produce highest α-glucosidase inhibitory activity to Daphnia magna and Artemia salina. From the measurement of acute toxicity test, the value of obtained from Daphnia magna was 818,7 ppm and obtained from Artemia salina was 3698,0 ppm."

"Latar belakang: Respon tubuh terhadap Hipoksia hipobarik intermitten sering dimanfaatkan dalam proses pre-conditioning hipoksia. Hati sebagai penghasil energi utama dan tempat metabolisme tubuh sangat terdampak dari kondisi hipoksia. Tujuan: Menganalisa perubahan enzim metabolisme pada hati tikus yang mengalami hipoksia hipobarik intermitten. Metode: Tikus Wistar dibagi menjadi 5 kelompok (n=5 perkelompok). Kelompok kontrol diberikan perlakuan normoksia. Kelompok perlakuan diberikan induksi hipoksia hipobarik intermitten menggunakan hypobaric chamber pada ketinggian 25000 kaki selama 1,2,3 dan 4 kali. Tikus kemudian dikorbankan pada ketinggian 5000 kaki dan diukur aktivitas spesifik enzim LDH pada 450 nm. Hasil: Aktivitas spesifik enzim LDH pada jaringan hati yang mengalami hipoksia hipobarik intermitten meningkat secara signifikan (p<0,05), dengan peningkatan tertinggi pada 3 kali pajanan. Simpulan: Hipoksia hipobarik intermitten menyebabkan peningkatan aktivitas spesifik enzim LDH.

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Backgrounds: Body response to intermittent hypoxia hypobaric frequently used as pre-conditioning hypoxia. This condition affected the liver as an energy supplier and body metabolism location.

Aim: Compare metabolism enzyme response in the liver that affected by intermittent hypoxia hypobaric.

Methods: Mice were divided into five groups (n=5 per group). Control group was given normoxia condition. Meanwhile exposed groups were given 1, 2, 3, and 4 times hypoxia hypobaric intermittent exposure. The exposure was using a hypobaric chamber at 25,000 feet. All of the LDH specific activities in the liver were measured at 450 nm.

Results: LDH specific activities in the liver increased significantly (p<0,05). The peak activity was found at 3 times hypoxia hypobaric intermittent exposure.

Conclusion: LDH specific activities in the liver that affected by hypoxia hypobaric intermittent increased significantly."

"Fruktansukrase merupakan enzim ekstraselular yang biasanya diproduksi oleh Bakteri Asam Laktat (BAL). Oleh BAL, enzim ini digunakan untuk memproduksi eksopolisakarida (EPS) dari substrat sukrosa maupun substrat rafinosa. EPS memiliki potensi yang besar dalam industri farmasi, pangan dan kesehatan. Dalam penelitian sebelumnya, Fruktansukrase rekombinan diklon ke dalam Bacillus subtilis DB 403 dan dirancang untuk disekresikan keluar sel. Penelitian ini bertujuan untuk mengisolasi protein fruktansukrase rekombinan dari bakteri Bacillus subtilis dan untuk mengetahui aktivitas fruktansukrase rekombinan tersebut. Pada penelitian ini, Bacillus subtilis rekombinan ditumbuhkan dan dipanen untuk mendapatkan protein fruktansukrase di dalam supernatan kultur. Protein dieksresikan secara ekstraselular. Ke dalam supernatan lalu ditambahkan PMSF untuk mencegah terjadinya degradasi oleh protease. Selanjutnya protein diliofilisasi dengan metode freeze dry. Pelet protein diresuspensikan dalam sejumlah kecil buffer sedemikian rupa sehingga konsentrasinya pekat, setelah itu difiltrasi dengan menggunakan Amicon® Ultra-15 Centrifugal Filter Device cutoff -30 kDa untuk memisahkan fraksi protein yang berukuran besar dan kecil. Fraksi protein yang lebih besar dari 30 kDa dikumpulkan, kemudian dianalisis dengan SDS-PAGE. Sebagian fraksi tersebut dianalisis secara in situ dengan PAS-staining. Aktivitas fruktansukrase dapat diamati pada gel yang diinkubasi dengan substrat sukrosa dan substrat rafinosa berupa pita berwarna pink intensif.

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Fructansucrase is an extracellular enzyme which usually produced by Lactic Acid Bacteria (LAB). By LAB, this enzyme is used to produce exopolysaccharide (EPS) from both sucrose and rafinose substrates. EPS has huge potential in pharmaceutical, food and health industries. In previous research, fructansucrase recombinant was cloned into Bacillus subtilis DB 403 and was designed to be secreted extracelullarly. This research aims to isolate the recombinant protein fructansucrase from Bacillus subtilis and to understand the activity of this recombinant fructansucrase. Bacillus subtilis was grown and extracted to obtain the fructansucrase protein within the culture supernatant. PMSF was added into the supernatant to prevent any degradation by proteases. The supernatant was liofilized using freeze-dry method. The protein pellets were then resuspended with small volume of buffer to obtain a more concentrated sample. Subsequently, the protein was filtrated using Amicon® Ultra-15 Centrifugal Filter Device cutoff -30 kDa to separate protein filtrate by size. Protein fraction which was larger than 30 kDa was collected and analyzed by SDS PAGE. Some of the fraction was analyzed in situ using PAS-staining. Fructansucrase activity is observed on gel after incubation with both sucrose and raffinose substrate as a pink intensive band."