Spermidine synthase (Spds) catalyzes the formation of spermidine by transferring the aminopropyl group from decarboxylated S-adenosylmethionine (dcSAM) to putrescine. The Synechococcus spds gene encoding Spds was expressed in Escherichia coli. The purified recombinant enzyme had a molecular mass of 33 kDa and showed optimal activity at pH 7.5, 37 °C. The enzyme had higher affinity for dcSAM (K , 20 µM) than for putrescine (K , 111 µM) and was highly specific towards the diamine putrescine with no activity observed towards longer chain diamines. The three-dimensional structural model for Synechococcus Spds revealed that most of the ligand binding residues in Spds from Synechococcus sp. PCC 7942 are identical to those of human and parasite Spds. Based on the model, the highly conserved acidic residues, Asp89, Asp159 and Asp162, are involved in the binding of substrates putrescine and dcSAM and Pro166 seems to confer substrate specificity towards putrescine.
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http://dx.doi.org/10.1007/s11274-017-2242-5 | DOI Listing |
Purpose: Understanding the molecular mechanisms of adaptive regulation in the tumor microenvironment is crucial for precision therapy in hepatocellular carcinoma (HCC). We hypothesized that cargo proteins carried by extracellular vesicles (EVs) released in a hypoxic microenvironment might promote HCC progression by remodeling tumor-associated macrophages (TAMs).
Methods: EV protein analysis by label-free proteomics mass spectrometry of HCC cell lines of different tumor grades was performed.
In Silico Pharmacol
December 2024
Laboratory of Cell and Molecular Biology, Department of Botany, Centre of Advanced Study, University of Calcutta, 35 Ballygunge Circular Road, Kolkata, 700019 India.
Visceral Leishmaniasis, caused by is the second most deadly parasitic disease, causing over 65,000 deaths annually. Synthetic drugs available in the market, to combat this disease, have numerous side effects. In this backdrop, we aim to find safer antileishmanial alternatives with minimal side effects from mushrooms, which harbour various secondary metabolites with promising efficacy.
View Article and Find Full Text PDFGut Microbes
December 2024
Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
Enteropathogenic (EPEC) is a bacterium that causes attaching/effacing (A/E) lesions and serious diarrheal disease, a major health issue in developing countries. EPEC pathogenicity results from the effect of virulence factors and dysregulation of host responses. Polyamines, including spermidine, play a major role in intestinal homeostasis.
View Article and Find Full Text PDFJ Biol Chem
December 2024
Faculty of Science and Engineering, Department of Biology, Konan University, Kobe, Japan; Institute of Integrative Neurobiology, Konan University, Kobe, Japan. Electronic address:
Phosphate (Pi) homeostasis at the cellular level is crucial, requiring coordinated Pi uptake, storage, and export. However, the regulatory mechanisms, particularly those governing Pi export, remain elusive, despite their relevance to human diseases like primary familial brain calcification. While Xpr1, conserved across eukaryotes, is the only known Pi exporter, the existence of additional Pi exporting factors is evident; however, these factors have been poorly characterized.
View Article and Find Full Text PDFJ Hazard Mater
November 2024
National Key Laboratory for Tropical Crop Breeding, School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572025, China; Key Laboratory for Quality Regulation of Tropical Horticultural Crops of Hainan Province, School of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China. Electronic address:
The vanadium (V) toxicity predominantly is the primary limitation in restraining pepper growth. The silicon (Si) in pepper plants induced the transcript level of the polyamines metabolism pathway genes, including the arginase (CbARG), ornithine decarboxylase (CbODC), arginine decarboxylase (CbADC), N-carbamoylputrescine amidase (CbNCA), Spermidine synthase (CbSPDS), copper binding diamine oxidase (CbCuAO) to overcome the V toxicity. The polyamines, including the Spm, Spd, and Put, induced with Si about 41.
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