Incubation of rat liver cytosolic isocitrate dehydrogenase with N-ethylmaleimide (NEM) resulted in the inactivation of the enzyme following pseudo-first order kinetics. Isocitrate affords considerable protection against inactivation whereas NADP+ enhances modification of the enzyme, suggesting localization of the modified group at the active site. Correlation of loss of activity with incorporation of [14C]NEM indicated that two sulphydryl residues/sub-unit are modified of which only one is shown to be involved in catalysis. pH dependence of the inactivation process implicates a reactive group of pKa 8.1 in catalysis. We conclude that a unique cysteine residue is essential for maximal catalytic activity of isocitrate dehydrogenase.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/0014-5793(93)81579-o | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Olutasidenib in combination with azacitidine induces durable complete remissions in patients with relapsed or refractory mIDH1 acute myeloid leukemia: a multicohort open-label phase 1/2 trial.
J Hematol Oncol
January 2025
Sylvester Comprehensive Cancer Center, University of Miami, Miami, FL, USA.
Background: Olutasidenib is a potent, selective, oral, small molecule inhibitor of mutant IDH1 (mIDH1) which induced durable remissions in high-risk, relapsed/refractory (R/R) mIDH1 AML patients in a phase 1/2 trial. We present a pooled analysis from multiple cohorts of the phase 1/2 trial of patients with R/R AML who received combination olutasidenib and azacitidine therapy.
Methods: Adult patients with mIDH1 AML received 150 mg olutasidenib twice daily plus standard-of-care azacitidine (OLU + AZA) and were evaluated for response and safety.
The role of glioma-associated myeloid cells in tumor growth and immune evasion remains poorly understood. We performed single-cell RNA sequencing of immune and tumor cells from 33 gliomas, identifying two distinct myeloid-derived suppressor cell (MDSC) populations in isocitrate dehydrogenase-wild-type (IDT-WT) glioblastoma: an early progenitor MDSC (E-MDSC) population with up-regulation of metabolic and hypoxia pathways and a monocytic MDSC (M-MDSC) population. Spatial transcriptomics demonstrated that E-MDSCs geographically colocalize with metabolic stem-like tumor cells in the pseudopalisading region.
View Article and Find Full Text PDFPrognostic value of CTF1 in glioma and its role in the tumor microenvironment.
Transl Cancer Res
December 2024
Department of Radiation Oncology, The Second Hospital of Lanzhou University, Lanzhou, China.
Background: Within the realm of primary brain tumors, specifically glioblastoma (GBM), presents a notable obstacle due to their unfavorable prognosis and differing median survival rates contingent upon tumor grade and subtype. Despite a plethora of research connecting cardiotrophin-1 (CTF1) modifications to a range of illnesses, its correlation with glioma remains uncertain. This study investigated the clinical value of CTF1 in glioma and its potential as a biomarker of the disease.
View Article and Find Full Text PDFMetabolomic characterisation of the glioblastoma invasive margin reveals a region-specific signature.
Heliyon
January 2025
Children's Brain Tumour Research Centre, School of Medicine, Biodiscovery Institute, University of Nottingham, UK.
Isocitrate dehydrogenase wild-type glioblastoma (GBM) is characterised by a heterogeneous genetic landscape resulting from dynamic competition between tumour subclones to survive selective pressures. Improvements in metabolite identification and metabolome coverage have led to increased interest in clinically relevant applications of metabolomics. Here, we use liquid chromatography-mass spectrometry and gene expression microarray to profile integrated intratumour metabolic heterogeneity, as a direct functional readout of adaptive responses of subclones to the tumour microenvironment.
View Article and Find Full Text PDFDiscontiguous recurrences of IDH-wildtype glioblastoma share a common origin with the initial tumor and are frequently hypermutated.
Acta Neuropathol Commun
January 2025
Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA.
Glioblastoma is the deadliest primary brain tumor, largely due to inevitable recurrence of the disease after treatment. While most recurrences are local, patients rarely present with a new discontiguous focus of glioblastoma. Little is currently known about the genetic profile of discontiguous recurrences.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!