scholarly journals Structural and Functional Characterization of a New Double Variant Haemoglobin (HbG-Philadelphia/Duarte α268Asn→Lysβ262Ala→Pro)

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Antonella Fais ◽  
Mariano Casu ◽  
Paolo Ruggerone ◽  
Matteo Ceccarelli ◽  
Simona Porcu ◽  
...  
Keyword(s):  
Md Simulation ◽  
Tertiary Structure ◽  
Functional Characterization ◽  
Protein A ◽  
Oxygen Affinity ◽  
Functional Study ◽  
Substitution Effects ◽  
Simulation Studies ◽  
First Case

We report the first case of cosegregation of two haemoglobins (Hbs): HbG-Philadelphia [α68(E17)Asn→Lys] and HbDuarte [β62(E6)Ala→Pro]. The proband is a young patient heterozygous also for β∘-thalassaemia. We detected exclusively two haemoglobin variants: HbDuarte and HbG-Philadelphia/Duarte. Functional study of the new double variant HbG-Philadelphia/Duarte exhibited an increase in oxygen affinity, with a slight decrease of cooperativity and Bohr effect. This functional behaviour is attributed to β62Ala→Pro instead of α68Asn→Lys substitution. Indeed, HbG-Philadelphia isolated in our laboratory from blood cells donor carrier for this variant is not affected by any functional modification, whereas purified Hb Duarte showed functional properties very similar to the double variant. NMR and MD simulation studies confirmed that the presence of Pro instead of Ala at the β62 position produces displacement of the E helix and modifications of the tertiary structure. The substitution α68(E17)Asn→Lys does not cause significant structural and dynamical modifications of the protein. A possible structure-based rational of substitution effects is suggested.

Hemoglobin Dallas (α97(G4)Asn→Lys):functional characterization of a high oxygen affinity natural mutant

1992 ◽  
Vol 1180 (1) ◽  
pp. 15-20 ◽  
Author(s):  
E. Lendaro ◽  
R. Ippoliti ◽  
A. Brancaccio ◽  
A. Bellelli ◽  
B. Vallone ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
High Oxygen Affinity

scholarly journals Functional Characterization of pGKT2, a 182-Kilobase Plasmid Containing the xplAB Genes, Which Are Involved in the Degradation of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine by Gordonia sp. Strain KTR9

2010 ◽  
Vol 76 (19) ◽  
pp. 6329-6337 ◽  
Author(s):  
Karl J. Indest ◽  
Carina M. Jung ◽  
Hao-Ping Chen ◽  
Dawn Hancock ◽  
Christine Florizone ◽  
...  
Keyword(s):  
Amino Acid Sequence Identity ◽  
Inorganic Nitrogen ◽  
Cytochromes P450 ◽  
Functional Characterization ◽  
Protein A ◽  
Nitrogen Sources ◽  
Pcr Analysis ◽  
Bacterial Cells ◽  
Glutamine Synthase

ABSTRACT Several microorganisms have been isolated that can transform hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a cyclic nitramine explosive. To better characterize the microbial genes that facilitate this transformation, we sequenced and annotated a 182-kb plasmid, pGKT2, from the RDX-degrading strain Gordonia sp. KTR9. This plasmid carries xplA, encoding a protein sharing up to 99% amino acid sequence identity with characterized RDX-degrading cytochromes P450. Other genes that cluster with xplA are predicted to encode a glutamine synthase-XplB fusion protein, a second cytochrome P450, Cyp151C, and XplR, a GntR-type regulator. Rhodococcus jostii RHA1 expressing xplA from KTR9 degraded RDX but did not utilize RDX as a nitrogen source. Moreover, an Escherichia coli strain producing XplA degraded RDX but a strain producing Cyp151C did not. KTR9 strains cured of pGKT2 did not transform RDX. Physiological studies examining the effects of exogenous nitrogen sources on RDX degradation in strain KTR9 revealed that ammonium, nitrite, and nitrate each inhibited RDX degradation by up to 79%. Quantitative real-time PCR analysis of glnA-xplB, xplA, and xplR showed that transcript levels were 3.7-fold higher during growth on RDX than during growth on ammonium and that this upregulation was repressed in the presence of various inorganic nitrogen sources. Overall, the results indicate that RDX degradation by KTR9 is integrated with central nitrogen metabolism and that the uptake of RDX by bacterial cells does not require a dedicated transporter.

scholarly journals Clinical and Functional Characterization of a Novel URAT1 Dysfunctional Variant in a Pediatric Patient with Renal Hypouricemia

2019 ◽  
Vol 9 (17) ◽  
pp. 3479
Author(s):  
Blanka Stiburkova ◽  
Jana Bohata ◽  
Iveta Minarikova ◽  
Andrea Mancikova ◽  
Jiri Vavra ◽  
...  
Keyword(s):  
Pediatric Patient ◽  
Primary Care Physicians ◽  
Expression System ◽  
Functional Characterization ◽  
Functional Study ◽  
Sequencing Analysis ◽  
Coding Region ◽  
Cytoplasmic Staining ◽  
Renal Hypouricemia

Renal hypouricemia (RHUC) is caused by an inherited defect in the main (reabsorptive) renal urate transporters, URAT1 and GLUT9. RHUC is characterized by decreased concentrations of serum uric acid and an increase in its excretion fraction. Patients suffer from hypouricemia, hyperuricosuria, urolithiasis, and even acute kidney injury. We report the clinical, biochemical, and genetic findings of a pediatric patient with hypouricemia. Sequencing analysis of the coding region of SLC22A12 and SLC2A9 and a functional study of a novel RHUC1 variant in the Xenopus expression system were performed. The proband showed persistent hypouricemia (67–70 µmol/L; ref. range 120–360 µmol/L) and hyperuricosuria (24–34%; ref. range 7.3 ± 1.3%). The sequencing analysis identified common non-synonymous allelic variants c.73G > A, c.844G > A, c.1049C > T in the SLC2A9 gene and rare variants c.973C > T, c.1300C > T in the SLC22A12 gene. Functional characterization of the novel RHUC associated c.973C > T (p. R325W) variant showed significantly decreased urate uptake, an irregular URAT1 signal on the plasma membrane, and reduced cytoplasmic staining. RHUC is an underdiagnosed disorder and unexplained hypouricemia warrants detailed metabolic and genetic investigations. A greater awareness of URAT1 and GLUT9 deficiency by primary care physicians, nephrologists, and urologists is crucial for identifying the disorder.

scholarly journals Pancytopenia, Recurrent Infection, Poor Wound Healing, Heterotopia of the Brain Probably Associated with A Candidate Novel de Novo CDC42 Gene Defect: Expanding the Molecular and Phenotypic Spectrum

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 294
Author(s):  
Abdulaziz Asiri ◽  
Deemah Alwadaani ◽  
Muhammad Umair ◽  
Kheloud M. Alhamoudi ◽  
Mohammed H. Almuhanna ◽  
...  
Keyword(s):  
Wound Healing ◽  
Molecular Mechanisms ◽  
Rho Gtpase ◽  
De Novo ◽  
Functional Characterization ◽  
Substantial Reduction ◽  
Recurrent Infection ◽  
First Case ◽  
The Brain

CDC42 (cell division cycle protein 42) belongs to the Rho GTPase family that is known to control the signaling axis that regulates several cellular functions, including cell cycle progression, migration, and proliferation. However, the functional characterization of the CDC42 gene in mammalian physiology remains largely unclear. Here, we report the genetic and functional characterization of a non-consanguineous Saudi family with a single affected individual. Clinical examinations revealed poor wound healing, heterotopia of the brain, pancytopenia, and recurrent infections. Whole exome sequencing revealed a de novo missense variant (c.101C > A, p.Pro34Gln) in the CDC42 gene. The functional assays revealed a substantial reduction in the growth and motility of the patient cells as compared to the normal cells control. Homology three-dimensional (3-D) modeling of CDC42 revealed that the Pro34 is important for the proper protein secondary structure. In conclusion, we report a candidate disease-causing variant, which requires further confirmation for the etiology of CDC42 pathogenesis. This represents the first case from the Saudi population. The current study adds to the spectrum of mutations in the CDC42 gene that might help in genetic counseling and contributes to the CDC42-related genetic and functional characterization. However, further studies into the molecular mechanisms that are involved are needed in order to determine the role of the CDC42 gene associated with aberrant cell migration and immune response.

Functional characterization of the recombinant human tumour suppressor 101F6 protein, a cytochrome b561 homologue

2012 ◽  
Vol 153 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Mariam C. Recuenco ◽  
Md. Motiur Rahman ◽  
Yoichi Sakamoto ◽  
Fusako Takeuchi ◽  
Hiroshi Hori ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Protein A ◽  
Tumour Suppressor ◽  
Human Tumour ◽  
Cytochrome B561

scholarly journals Functional Characterization of KCNMA1 mutation associated with dyskinesia, seizure, developmental delay, and cerebellar atrophy

2021 ◽  
Author(s):  
Emrah Yucesan ◽  
Beyza Goncu ◽  
Cemil Ozgul ◽  
Arda Kebapci ◽  
Ayca Dilruba Aslanger ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Cerebellar Atrophy ◽  
Bk Channels ◽  
Bk Channel ◽  
Functional Study ◽  
Loss Of Function ◽  
Gain Of Function ◽  
Α Subunit ◽  
Truncating Mutation

Abstract KCNMA1 located on chromosome 10q22.3, encodes the pore-forming α subunit of the “Big K+” (BK) large conductance calcium and voltage-activated K + channel. BK channels are widely distributed across tissues, including both excitable and non excitable cells. Numerous evidence suggests the functional BK channel alterations produced by different KCNMA1 alleles may associate with different symptoms, such as paroxysmal non kinesigenic dyskinesia with gain of function and ataxia with loss of function. Functional classifications revealed two major patterns, gain of function and loss of function effects on channel properties in different cell lines. In the literature, two mutations have been shown to confer gain of function properties to BK channels: D434G and N995S. On the other hand 10 mutations have been classified as loss of function (S351Y,G354S, G356R, G375R, C413Y/N449fs, I663V, P805L, and D984N) or putative loss of function (premature truncation mutations: Y676Lfs*7 and Arg458Ter). In this study, we report the functional characterization of a variant which was previously reported the whole exome sequencing revealed bi-allelic nonsense variation (NM_001161352.1 (ENST00000286628.8):c.1372C > T; Arg458*) of the cytoplasmic domain of calcium-activated potassium channel subunit alpha-1 protein. To detect functional consequences of the variation immunostaining and electrophysiological studies were conducted. In this study, we conducted patch-clamp recordings on WT and R458X mutant cells. We found the gain of function effect for the mutation. This is the first functional study observing an increased current in the KCNMA1 gene resulting from a truncating mutation

Sign in / Sign up

Export Citation Format

Share Document