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All Journal HAYATI Journal of Biosciences Makara Journal of Science
NIKNIK NURHAYATI
Center for Bioindustrial Technology, Laboratorium of Bioindustrial Technology, LAPTIAB BPPT Puspiptek -Serpong
Agriculture, Biological Sciences & Forestry Earth & Planetary Sciences

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Sequence-Structure Based Comparison of Structurally Homologous Thermophilic and Mesophilic Polyethylene Terephthalate (PET) Hydrolases Hasan, Khomaini; Ulfah, Maria; Nurhayati, Niknik; Sabbathini, Gabriela Christy; Wulandari, Sri Rezeki; Putra, I Gede Eka Perdana; Helianti, Is
HAYATI Journal of Biosciences Vol. 31 No. 2 (2024): March 2024
Publisher : Bogor Agricultural University, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.4308/hjb.31.2.348-356

Abstract

Protein structure has a direct impact on thermostability. Deviations in the primary sequence can affect structural changes, leading to alterations in thermostability properties. However, the molecular basis of protein thermostability is unspecified; thus, elucidation of key factors that role particular protein thermostability is required when engineering proteins to be thermostable. To address this challenge, the amino acid composition, hydrophobicity/hydrophilicity ratio, cysteine bridges, and intrinsic features of two structurally homologous but different thermostability, poly(ethylene terephthalate) hydrolase (PETase) were compared. According to the findings, thermostable and thermolabile PETases have similar folds, compactness, and disulfide bridges. Interestingly, an abundance gap of aromaticity, hydrophobic cluster area, polar amino acid and hydrogen bond network compositions demonstrated dominant trends of variations for both PET hydrolases, indicating a pivotal role of these features in the thermostability of PET hydrolase. Furthermore, increased hydrophobic amino acid frequency in the inner surface of thermostable proteins contributed significantly to thermostability by forming more internal hydrophobic interactions and a less hydrophobic patch. There are no consistent trends in insertions and deletions between both PETases. Taken together, these observations demonstrate that hydrophobicity and hydrogen bond networks are essential factors in thermostability of thermostable PETase.
Optimizing the Expression of Polyethylene Terephtalate Hydrolase-Encoding Synthetic Gene in Escherichia coli Arctic Express (DE3) Nataniel, Jocelyn; Ulfah, Maria; Achnafani, Dini; Nurhayati, Niknik; Sabbathini, Gabriela Christy; Wulandari, Sri Rezeki; Abinawanto, Abinawanto; Helianti, Is
Makara Journal of Science Vol. 28, No. 2
Publisher : UI Scholars Hub

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Abstract

The waste of polyethylene terephthalate (PET) plastic waste in Indonesia is a pressing concern due to its slow degradation and potential environmental damage. One promising solution is to utilize polyethylene terephthalate hydrolase from Ideonella sakaiensis (IsPETase), an enzyme that specifically degrades PET. However, inducing the expression of IsPETase synthetic gene in Escherichia coli BL21 (DE3) has been challenging because much of it remains insoluble. This study aimed to express IsPETase in E. coli Arctic Express (DE3) and optimize the conditions to enhance its production. First, pET22b(+)pelB-IsPETase was inserted into E. coli Arctic Express (DE3). The recombinant E. coli Arctic Express (DE3) was induced with isopropyl-β-D-1-thiogalactopyranoside (IPTG) and incubated at 10 °C. The fraction expressing soluble IsPETase was determined in different culture media, IPTG concentrations, induction times, and soni-cation durations. Parameters were optimized using a one-factor-at-a-time approach and then evaluated based on esterase specific activity and SDS-PAGE analysis. Results showed that IsPETase can be expressed in extracellular, periplasmic, and cytoplasmic soluble fractions. However, the extracellular fraction should be concentrated. Subsequent optimization focused only on the cytoplasmic fraction under optimal conditions, achieving a threefold increase in PETase specific activity compared with that under uninduced IPTG conditions. The reaction of PETase enzyme with PET and PCL was proven by weight loss, Scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR). Although successful IsPETase expression and production optimization have been achieved, the specific activity remains low, prompting the need for ongoing expression optimization.
Co-Authors Abinawanto Abinawanto Achnafani, Dini I Gede Eka Perdana Putra, I Gede Eka Perdana IS HELIANTI KHOMAINI HASAN Maria Ulfah Nataniel, Jocelyn Sabbathini, Gabriela Christy Wulandari, Sri Rezeki