Polyethylene terephthalate (PET) is one of the most abundantly produced synthetic polyesters. The vast number of waste plastics including PET has challenged the waste management sector while also posing a serious threat to the environment due to improper littering. Recently, enzymatic PET degradation has been shown to be a viable option for a circular plastic economy, which can mitigate the plastic pollution. While protein engineering studies on specific PET degradation enzymes such as leaf-branch compost cutinase (LCC), Thermobifida sp. cutinases and Ideonella sakaiensis PETase (IsPETase) have been extensively published, other homologous PET degrading enzymes have received less attention. Ple629 is a polyester hydrolase identified from marine microbial consortium having activity on PET and the bioplastic polybutylene adipate terephthalate (PBAT). In order to explore its catalytic mechanism and improve its potential for PET hydrolysis, we solved its crystal structure in complex with a PET monomer analogue, and validated its structural and mechanistic similarity to known PET hydrolases. By structural comparisons, we identified some hot spot positions described in previous research on protein engineering of PET hydrolases. We substitute these amino acid residues in Ple629, and obtained variants with improved activity and thermo-stability. The most promising variant D226A/S279A exhibited a more than 5.5-fold improved activity on PET nanoparticles than the wild-type enzyme, suggesting its potential applicability in the biotechnological plastic recycling.
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http://dx.doi.org/10.1016/j.bbrc.2022.07.103 | DOI Listing |
Calcif Tissue Int
January 2025
Endocrinology Department, School of Medicine, Pontificia Universidad Católica de Chile, Av. Diagonal Paraguay 262, Cuarto Piso, Santiago, Chile.
X-linked hypophosphatemia (XLH) is a rare metabolic disorder characterized by elevated FGF23 and chronic hypophosphatemia, leading to impaired skeletal mineralization and enthesopathies that are associated with pain, stiffness, and diminished quality of life. The natural history of enthesopathies in XLH remains poorly defined, partly due to absence of a sensitive quantitative tool for assessment and monitoring. This study investigates the utility of 18F-NaF PET/CT scans in characterizing enthesopathies in XLH subjects.
View Article and Find Full Text PDFNPJ Aging
January 2025
Division of Cardiovascular Medicine, Department of Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume, Japan.
We investigated clinical factors and biochemical markers associated with amygdalar metabolic activity evaluated by [F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) in 346 subjects without a history of malignant neoplasms. Univariate regression analysis revealed significant relationships between amygdalar metabolic activity and fasting plasma glucose (FPG), glycated hemoglobin, coronary artery disease (CAD) history, aspirin use, oral hypoglycemic agents (OHAs) use, and asymmetric dimethylarginine (ADMA). In multiple stepwise regression analysis, FPG and CAD history were independently associated with amygdalar metabolic activity.
View Article and Find Full Text PDFZhonghua Nei Ke Za Zhi
February 2025
Department of Endocrinology, the First Affiliated Hospital of Chongqing Medical University, Chongqing400016, China.
Acad Radiol
January 2025
Department of Radiology, Washington University School of Medicine, 510 S. Kingshighway Blvd, St. Louis, MO 63110 (S.I., M.A.T., M.I., C.S., R.L., A.H., R.L.W., T.J.F.). Electronic address:
Rationale And Objective: Conventional positron emission tomography (PET) respiratory gating utilizes a fraction of acquired PET counts (i.e., optimal gate [OG]), whereas elastic motion correction with deblurring (EMCD) utilizes all PET counts to reconstruct motion-corrected images without increasing image noise.
View Article and Find Full Text PDFJ Prev Alzheimers Dis
February 2025
Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, China, 154 Anshan Road Tianjin 300052, PR China; Department of Neurology, Tianjin Medical University General Hospital Airport Site, Tianjin 300052, PR China. Electronic address:
Background: Changes in cerebral blood flow (CBF) may contribute to the initial stages of the pathophysiological process in patients with Alzheimer's disease (AD). Hypoperfusion has been observed in several brain regions in patients with mild cognitive impairment (MCI). However, the clinical significance of CBF changes in the early stages of AD is currently unclear.
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