Judul: Pemurnian protease dari daun mengkudu (Morinda citrifolia L.)
Abstrak: It has been proved that protease could tenderize meat and octopuses. One of the protease sources is noni (Morinda citrifolias L.) leaves. Yet, the study of proteases in noni leaves has not been reported. The research was aimed to characterize physic and chemistry of noni leaves and purify the protease of noni leaves both from base and shoot part. The physic and chemistry characterization of noni leaves was done by observation and proximate analysis, respectively. The purification of noni leaves proteases was conducted by several steps consisting of extraction, centrifugation, precipitation using saturated ammonium sulfate (100%), dialysis and electrophoresis also zymography. The noni leaves used in this research have facing position, large and thick size, single, flat edge, pinnate veins, green-shiny color, and hairless. Base leaves are dark green dan shoot leaves are light green. The proximate analysis showed that the protein content of base noni leaves (2.92%dry base) was lower than shoot leaves (2.98% dry base). Purification of noni leaves proteases showed that the crude extract of base leaves had higher enzyme specific activity (0.46U/mg protein) than the crude extract of shoot leaves (0.43U/mg protein). Protein content of base leaves (11.29%) was lower than the other (11.47%). Noni leaves purification steps decreased protease specific activity. SDS-PAGE of shoot and base leaves dialysates showed the polypeptides molecular weights were 58- 61.5kDa and 70kDa respectively; whereas zymogram showed the molecular weight of the enzymes are 39kDa and 50kDa.
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Judul: Pemurnian dan pencirian protease dari ekstrak jamur merang
Abstrak: Enzim protease dari jamur merang (Volvariela volvaceae) yang terdapat di Indonesia memiliki aktivitas fibrinolitik. Penelitian ini bertujuan memurnikan dan mencirikan protease dari ekstrak jamur merang. Ekstrak enzim jamur merang dimurnikan dengan presipitasi amonium sulfat kejenuhan 75%, dialisis (cut off 10 KD), dan kromatografi penukar ion DEAE Sepharose. Pemurnian menghasilkan satu fraksi enzim aktif. Aktivitas spesifik fraksi aktif adalah 0.383 U/mg, dengan tingkat kemurnian 2.681 kali dibandingkan dengan ekstrak enzim kasar. Hasil analisis SDS-PAGE memperlihatkan fraksi aktif protease terdiri atas dua pita protein (15.8 dan 12.9 KD). Aktivitas optimum protease dicapai pada suhu 50 oC dan pH 7. Uji zimogram memperlihatkan bahwa protease mampu menghidrolisis substrat kasein dan fibrinogen dengan konsentrasi 0.01% (b/v). Aktiv itas enzim protease menurun dengan penambahan ion Fe3+. Protease ekstrak kasar dihambat spesifik oleh inhibitor fenilmetilsulfonil fluorida dan N-p-tosil-L-lisinklorometil keton sehingga digolongkan ke dalam kelompok protease serin. ABSTRACT SOLIHATI. Purification and Characterization of Protease from Extract of Straw Mushroom. Under the direction of IRMA H SUPARTO and YANTI. An Indonesian straw mushroom believed to have protease which has fibrinolytic activity. Therefore, the purpose of this research was to study the purification and characterization of protease from crude extract of straw mushroom (Volvariela volvaceae). The extracted straw mushroom went through several steps of purification using ammonium sulfate 75% saturation, dialyzed (cut-off 10 KD), and ion-exchange chromatographed using DEAE Sepharose. The result of the study showed one active fraction of enzyme. The spesific activity of this fraction was 0.383 U/mg, compared to the crude extract it has 2.681 fold high er purification. The enzyme revealed two protein bands at active fraction (15.8 and 12.9 KD) by SDS-PAGE. Its optimum activity was achieved at pH 7 and temperature 50 oC. The Protease effectively hydrolyzed casein and fibrinogen at 0.01% concentration by zymogram. The protease enzyme activity decreased by the addition of ion Fe3+ 5 mM. This enzyme was inhibited strongly by phenylmethylsulphonyl fluoride and N-p-tosyl-L-lysinchloromethyl keton. Therefore, this enzyme that was purified from straw mushroom can be classified as serine protease.
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Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular