Human 25-hydroxyvitamin D-24-hydroxylase has been expressed in Spodoptera frugiperda (Sf21) insect cells using the previously cloned cDNA in baculovirus (AcNPV-P450cc24). The activity of recombinant h-P450cc24 required adrenodoxin, adrenodoxin reductase, and NADPH. Incubation of this reconstituted system with 25-OH-[26,27-(3)H]D3 substrate produced several metabolites that were resolved on a normal-phase cyano HPLC system. These products exactly comigrated with authentic standards for 24-oxo-25-OH-D3, 23(S),25-(OH)2D3, 24(R),25-(OH)2D3, and 24-oxo-23(S),25-(OH)2D3. The soluble proteins from Sf21 cells infected with wild-type baculovirus produced neither 24,25-(OH)2D3 nor any of the other 25-OH-D3 metabolites. The products were isolated and subjected to a normal-phase amino HPLC for further separation, purification, and characterization. Comigration on two HPLC systems, periodate cleavage reactions, and NaBH4 reduction established clearly the identity of these metabolites. Incubation of recombinant h-P450cc24 with 25-OH-[3 alpha-3H]D3 led to the isolation of an additional product that comigrated with 24,25,26,27-tetranor-23-OH-D3. Treatment of putative 24,25,26,27-tetranor-23-OH-[3 alpha-3H]D3 with acetic anhydride changed its migration on amino HPLC to a less polar position, indicating acetylation of a hydroxyl group(s). These data demonstrate conclusively that h-P450cc24 is a multicatalytic enzyme catalyzing most, if not all, of the reactions in the C-24/C-23 pathway of 25-OH-D3 metabolism. It is likely that this enzyme by itself converts 25-OH-D3 and 1,25-(OH)2D3 to one of its final excretion products.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/bi960658i | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Micronutrient status and risk of Mycobacterium tuberculosis infection in Indonesian tuberculosis case contacts.
Trans R Soc Trop Med Hyg
January 2025
Research Center for Care and Control of Infectious Disease, Universitas Padjadjaran, Bandung 45363, Indonesia.
Background: Certain micronutrient levels have been associated with the risk of developing TB disease. We explored the possible association of selected at-risk micronutrient levels with the development of Mycobacterium tuberculosis (M.tb) infection.
View Article and Find Full Text PDFNeuroprotective and inflammatory biomarkers in pediatric drug-resistant epilepsy: Interplay between GDNF, IL-1β and vitamin D 25-OH.
Narra J
December 2024
Department of Clinical Pathology, Faculty of Medicine, Universitas Imelda, Medan, Indonesia.
Drug-resistant epilepsy in pediatric patients is associated with neuroinflammation and neurodegeneration. Vitamin D 25-OH exerts neuroprotective effects, while glial cell line- derived neurotrophic factor (GDNF) and the proinflammatory cytokine interleukin-1β (IL-1β) are implicated in the mechanisms of neuroinflammation and epileptogenesis. The aim of this study was to investigate the relationship between vitamin D 25-OH, IL-1β, and GDNF levels with seizure severity and frequency in children with drug-resistant epilepsy.
View Article and Find Full Text PDFGenetic Variants Associated with the Biochemical Response to Vitamin D3 in the Multi-Ethnic Study of Atherosclerosis.
J Clin Endocrinol Metab
January 2025
Kidney Research Institute, Department of Medicine, University of Washington, Seattle, WA.
Context: The response to treatment with vitamin D varies between patients.
Objective: To identify genetic variants associated with the biochemical response to vitamin D3 supplementation.
Design: Randomized placebo-controlled trial conducted between 2017 and 2019.
The Relationship Between Novel Inflammatory Markers and Serum 25-Hydroxyvitamin D Among US Adults.
Immun Inflamm Dis
January 2025
Department of Cardiology, Anqing First People's Hospital of Anhui Medical University, Anqing, China.
Background: Vitamin D is the focus of extensive medical research globally. Recent studies have investigated the correlation between serum 25-hydroxyvitamin D (25(OH)D) and common inflammatory markers. However, few studies have incorporated novel inflammatory markers such as the platelet-to-lymphocyte ratio (PLR), platelet-to-high density lipoprotein cholesterol ratio (PHR), systemic inflammatory index (SII), neutrophil-to-lymphocyte ratio (NLR), systemic inflammatory response (SIRI), and neutrophil-to-high-density lipoprotein cholesterol ratio (NHR).
View Article and Find Full Text PDFCombined 25-hydroxyvitamin D concentrations and physical activity on mortality in US stroke survivors: findings from the NHANES.
Nutr J
January 2025
Department of Neurology, Affiliated Hospital of Nanjing University of Chinese Medicine, 155 Hanzhong Road, Nanjing, 210029, China.
Background: 25-hydroxyvitamin D [25(OH)D] concentrations and physical activity (PA) are linked and both are associated with changes in mortality. We examined the association of 25(OH)D and PA with all-cause or cause-specific mortality risk in stroke survivors.
Methods: The analysis included 677 stroke survivors from National Health and Nutrition Examination Survey (NHANES) 2007-2008 to 2017-2018.
Want 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!