| 1. |
- Dobritzsch, Doreen, 1972-, et al.
(författare)
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beta-Ureidopropionase deficiency due to novel and rare UPB1 mutations affecting pre-mRNA splicing and protein structural integrity and catalytic activity
- 2022
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Ingår i: Molecular Genetics and Metabolism. - : Elsevier. - 1096-7192 .- 1096-7206. ; 136:3, s. 177-185
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Tidskriftsartikel (refereegranskat)abstract
- beta-Ureidopropionase is the third enzyme of the pyrimidine degradation pathway and catalyses the conversion of N-carbamyl-beta-alanine and N-carbamyl-beta-aminoisobutyric acid to beta-alanine and beta-aminoisobutyric acid, ammonia and CO2. To date, only a limited number of genetically confirmed patients with a complete beta-ureidopropionase deficiency have been reported. Here, we report on the clinical, biochemical and molecular findings of 10 newly identified beta-ureidopropionase deficient individuals. Patients presented mainly with neurological abnormalities and markedly elevated levels of N-carbamyl-beta-alanine and N-carbamyl-beta-aminoisobutyric acid in urine. Analysis of UPB1, encoding beta-ureidopropionase, showed 5 novel missense variants and two novel splice-site variants. Functional expression of the UPB1 variants in mammalian cells showed that recombinant beta-ureidopropionase carrying the p.Ala120Ser, p.Thr129Met, p.Ser300Leu and p.Asn345Ile variant yielded no or significantly decreased beta-ureidopropionase activity. Analysis of the crystal structure of human beta-ureidopropionase indicated that the point mutations affect substrate binding or prevent the proper subunit association to larger oligomers and thus a fully functional beta-ureidopropionase. A minigene approach showed that the intronic variants c.[364 + 6 T > G] and c.[916 + 1_916 + 2dup] led to skipping of exon 3 and 8, respectively, in the process of UPB1 pre-mRNA splicing. The c.[899C > T] (p.Ser300Leu) variant was identified in two unrelated Swedish beta-ureidopropionase patients, indicating that beta-ureidopropionase deficiency may be more common than anticipated.
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| 2. |
- Filieri, Antonio, et al.
(författare)
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Automated Design of Self-Adaptive Software with Control-Theoretical Formal Guarantees
- 2015
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Ingår i: Software Engineering and Management 2015 : Multikonferenz der GI-Fachbereiche Softwaretechnik (SWT) und Wirtschaftsinformatik (WI), FA WI-MAW - Multikonferenz der GI-Fachbereiche Softwaretechnik (SWT) und Wirtschaftsinformatik (WI), FA WI-MAW. - 1617-5468. - 9783885796336 ; P-239, s. 112-113
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Konferensbidrag (refereegranskat)abstract
- Self-adaptation enables software to execute successfully in dynamic, unpredictable, and uncertain environments. However, most of the current approaches lack formal guarantees on the effectiveness and dependability of the adaptation mechanisms, limiting their applicability in practice. Control theory established a broad set of mathematically grounded techniques for the control of dynamic systems for several engineering fields. While control shares self-evident similarities with software adaptation, modeling software behavior as a system of differential or difference equations is not straightforward, nor is mastering the mathematical background needed for synthesizing a suitable controller. In this paper we focus on the automatic modeling and controller synthesis for systems with a single knob affecting the satisfaction of a quantitative requirements. Effectiveness and performance of the controller are guaranteed by construction. The approach is fully automated and implemented in several programming languages, empowering non-experts with the ability of applying control principles to a wide range of software adaptation problems.
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| 3. |
- van Kuilenburg, André B P, et al.
(författare)
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Dihydropyrimidinase deficiency : Phenotype, genotype and structural consequences in 17 patients
- 2010
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Ingår i: Biochimica et Biophysica Acta - Molecular Basis of Disease. - : Elsevier BV. - 0925-4439 .- 1879-260X. ; 1802:7-8, s. 639-648
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Tidskriftsartikel (refereegranskat)abstract
- Dihydropyrimidinase (DHP) is the second enzyme of the pyrimidine degradation pathway and catalyses the ring opening of 5,6-dihydrouracil and 5,6-dihydrothymine. To date, only 11 individuals have been reported suffering from a complete DHP deficiency. Here, we report on the clinical, biochemical and molecular findings of 17 newly identified DHP deficient patients as well as the analysis of the mutations in a three-dimensional framework. Patients presented mainly with neurological and gastrointestinal abnormalities and markedly elevated levels of 5,6-dihydrouracil and 5,6-dihydrothymine in plasma, cerebrospinal fluid and urine. Analysis of DPYS, encoding DHP, showed nine missense mutations, two nonsense mutations, two deletions and one splice-site mutation. Seventy-one percent of the mutations were located at exons 5-8, representing 41% of the coding sequence. Heterologous expression of 11 mutant enzymes in Escherichia coli showed that all but two missense mutations yielded mutant DHP proteins without significant activity. Only DHP enzymes containing the mutations p.R302Q and p.T343A possessed a residual activity of 3.9% and 49%, respectively. The crystal structure of human DHP indicated that the point mutations p.R490C, p.R302Q and p.V364M affect the oligomerization of the enzyme. In contrast, p.M70T, p.D81G, p.L337P and p.T343A affect regions near the di-zinc centre and the substrate binding site. The p.S379R and p.L7V mutations were likely to cause structural destabilization and protein misfolding. Four mutations were identified in multiple unrelated DHP patients, indicating that DHP deficiency may be more common than anticipated.
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| 4. |
- van Kuilenburg, André B P, et al.
(författare)
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ß-ureidopropionase deficiency : phenotype, genotype and protein structural consequences in 16 patients
- 2012
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Ingår i: Biochimica et Biophysica Acta. - : Elsevier BV. - 0006-3002 .- 1878-2434. ; 1822:7, s. 1096-108
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Tidskriftsartikel (refereegranskat)abstract
- ß-ureidopropionase is the third enzyme of the pyrimidine degradation pathway and catalyzes the conversion of N-carbamyl-ß-alanine and N-carbamyl-ß-aminoisobutyric acid to ß-alanine and ß-aminoisobutyric acid, ammonia and CO(2). To date, only five genetically confirmed patients with a complete ß-ureidopropionase deficiency have been reported. Here, we report on the clinical, biochemical and molecular findings of 11 newly identified ß-ureidopropionase deficient patients as well as the analysis of the mutations in a three-dimensional framework. Patients presented mainly with neurological abnormalities (intellectual disabilities, seizures, abnormal tonus regulation, microcephaly, and malformations on neuro-imaging) and markedly elevated levels of N-carbamyl-ß-alanine and N-carbamyl-ß-aminoisobutyric acid in urine and plasma. Analysis of UPB1, encoding ß-ureidopropionase, showed 6 novel missense mutations and one novel splice-site mutation. Heterologous expression of the 6 mutant enzymes in Escherichia coli showed that all mutations yielded mutant ß-ureidopropionase proteins with significantly decreased activity. Analysis of a homology model of human ß-ureidopropionase generated using the crystal structure of the enzyme from Drosophila melanogaster indicated that the point mutations p.G235R, p.R236W and p.S264R lead to amino acid exchanges in the active site and therefore affect substrate binding and catalysis. The mutations L13S, R326Q and T359M resulted most likely in folding defects and oligomer assembly impairment. Two mutations were identified in several unrelated ß-ureidopropionase patients, indicating that ß-ureidopropionase deficiency may be more common than anticipated.
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