scholarly journals Structural and Functional Characterization of Four Novel Fibrinogen Mutations in FGB Causing Congenital Fibrinogen Disorder

2022 ◽  
Vol 23 (2) ◽  
pp. 721
Author(s):  
Eliška Ceznerová ◽  
Jiřina Kaufmanová ◽  
Žofie Sovová ◽  
Jana Štikarová ◽  
Jan Loužil ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Abnormal Development ◽  
Screening Tests ◽  
Morphological Properties ◽  
Fiber Density ◽  
Reverse Phase ◽  
Gene Coding ◽  
Novel Variants ◽  
Fiber Thickness

Congenital fibrinogen disorders are caused by mutations in genes coding for fibrinogen and may lead to various clinical phenotypes. Here, we present a functional and structural analysis of 4 novel variants located in the FGB gene coding for fibrinogen Bβ chain-heterozygous missense BβY416C and BβA68S, homozygous nonsense BβY345*, and heterozygous nonsense BβW403* mutations. The cases were identified by coagulation screening tests and further investigated by various methods. Fibrin polymerization had abnormal development with decreased maximal absorbance in all patients. Plasmin-induced fibrin degradation revealed different lytic phases of BβY416C and BβW403* than those of the control. Fibrinopeptide cleavage measured by reverse phase high pressure liquid chromatography of BβA68S showed impaired release of fibrinopeptide B. Morphological properties, studied through scanning electron microscopy, differed significantly in the fiber thickness of BβY416C, BβA68S, and BβW403*, and in the fiber density of BβY416C and BβW403*. Finally, homology modeling of BβA68S showed that mutation caused negligible alternations in the protein structure. In conclusion, all mutations altered the correct fibrinogen function or structure that led to congenital fibrinogen disorders.

scholarly journals Functional characterization of Candida albicans Hos2 histone deacetylase

F1000Research ◽  
2014 ◽  
Vol 2 ◽  
pp. 238
Author(s):  
G Karthikeyan ◽  
Maneesh Paul-Satyaseela ◽  
Nachiappan Dhatchana Moorthy ◽  
Radha Gopalaswamy ◽  
Shridhar Narayanan
Keyword(s):  
Candida Albicans ◽  
Histone Deacetylase ◽  
Trichostatin A ◽  
Functional Characterization ◽  
Gene Coding ◽  
Mold And Yeast ◽  
Anti Fungal ◽  
Vaginal Thrush ◽  
Inhibition Studies

Candida albicans is a mucosal commensal organism capable of causing superficial (oral and vaginal thrush) infections in immune normal hosts, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization of HOS2 (HighOsmolarity Sensitive), a gene coding for fungal histone deacetylase from C. albicans. Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such as MS-275. This in vitro enzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity.

Functional characterization of novel variants in SMPD1 in Indian Patients with Acid sphingomyelinase deficiency

2021 ◽  
Author(s):  
Dipti Deshpande ◽  
Shailesh Kumar Gupta ◽  
Asodu Sandeep Sarma ◽  
Prajnya Ranganath ◽  
Jamal Mohammed Nurul Jain S. ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Acid Sphingomyelinase ◽  
Sphingomyelinase Deficiency ◽  
Indian Patients ◽  
Novel Variants

scholarly journals TworsaMhomologues encode central regulatory elements modulating quorum sensing expression inBurkholderia thailandensis

2017 ◽  
Author(s):  
Servane Le Guillouzer ◽  
Marie-Christine Groleau ◽  
Eric Déziel
Keyword(s):  
Quorum Sensing ◽  
Functional Characterization ◽  
Gene Clusters ◽  
Homoserine Lactone ◽  
Regulatory Elements ◽  
Burkholderia Thailandensis ◽  
Gene Coding ◽  
Genes Expression ◽  
In The Wild

AbstractThe bacteriumBurkholderia thailandensispossesses three conservedN-acyl-L-homoserine lactone (AHL) quorum sensing (QS) systems designated BtaI1/BtaR1 (QS-1), BtaI2/BtaR2 (QS-2), and BtaI3/BtaR3 (QS-3). These QS-systems are associated with the biosynthesis ofN-octanoyl-homoserine lactone (C8-HSL),N-3-hydroxy-decanoyl-homoserine lactone (3OHC10-HSL), as well asN-3-hydroxy-octanoyl-homoserine lactone (3OHC8-HSL), which are produced by the LuxI-type synthase BtaI1, BtaI2, and BtaI3, and modulated by the LuxR-type transcriptional regulators BtaR1, BtaR2, and BtaR3. BothbtaR1/btaI1andbtaR2/btaI2gene clusters contain an additional gene that is conserved in theBurkholderiagenus, homologous to a gene coding for the negative AHL biosynthesis modulatory protein RsaM originally identified in the phytopathogenPseudomonas fuscovaginae, and hence designatedrsaM1andrsaM2. We have characterized the function of these tworsaMhomologues and demonstrated their involvement in the regulation of AHLs biosynthesis inB. thailandensisstrain E264. We measured the production of C8-HSL, 3OHC10-HSL, and 3OHC8-HSL by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) in the wild-type strain and in thersaM1-andrsaM2-mutants, and monitored the transcription ofbtaI1,btaI2, andbtaI3 using chromosomal mini-CTX-luxtranscriptional reporters. The expression ofbtaR1,btaR2, andbtaR3 was also measured by quantitative everse-transcription PCR (qRT-PCR). We demonstrate that the QS-1 system is repressed by RsaM1, whereas RsaM2 principally represses the QS-2 system. We also found that bothrsaM1andrsaM2are QS-controlled, as well as negatively auto-regulated. We conclude that RsaM1 and RsaM2 are an integral part of the QS modulatory circuitry ofB. thailandensis, and play a major role in the hierarchical and homeostatic organization of the QS-1, QS-2, and QS-3 systems.ImportanceQuorum sensing (QS) is a global regulatory mechanism of genes expression depending on bacterial density. QS is commonly involved in the coordination of genes expression associated with the establishment of host-pathogen interactions and acclimatization to the environment. We present the functional characterization of the tworsaMhomologues designatedrsaM1andrsaM2in the regulation of the multiple QS systems coexisting in the non-pathogenic bacteriumBurkholderia thailandensis, widely used as a model system for the study of the pathogenBurkholderia pseudomallei. We found that inactivation of thesersaMhomologues, which are clustered with the other QS genes, profoundly affects the QS regulatory circuity ofB. thailandensis. It is proposed that these genes code for QS repressors and we conclude that they constitute essential regulatory components of the QS modulatory network ofB. thailandensis, and provide additional layers of regulation to modulate the expression of QS-controlled genes, including those encoding virulence/survival factors and linked to environmental adaptation inB. pseudomallei.

Functional characterization of novel variants in the CETP promoter and the LIPC gene in subjects with hyperalphalipoproteinemia

2013 ◽  
Vol 416 ◽  
pp. 92-95 ◽  
Author(s):  
Wanee Plengpanich ◽  
Siraprapa Tongkobpetch ◽  
Vorasuk Shotelersuk ◽  
Wilfried Le Goff ◽  
Weerapan Khovidhunkit
Keyword(s):  
Functional Characterization ◽  
Novel Variants

scholarly journals Functional characterization of Candida albicans Hos2 histone deacetylase

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 238 ◽  
Author(s):  
G Karthikeyan ◽  
Maneesh Paul-Satyaseela ◽  
Nachiappan Dhatchana Moorthy ◽  
Radha Gopalaswamy ◽  
Shridhar Narayanan
Keyword(s):  
Candida Albicans ◽  
Histone Deacetylase ◽  
Trichostatin A ◽  
Functional Characterization ◽  
Gene Coding ◽  
Normal Individuals ◽  
Mold And Yeast ◽  
Anti Fungal ◽  
Inhibition Studies

Candida albicansis a mucosal commensal organism in normal individuals, but is a major pathogen causing systemic and mucosal infections in immunocompromised individuals. Azoles have been very effective anti-fungal agents and the mainstay in treating opportunistic mold and yeast infections. Azole resistant strains have emerged compromising the utility of this class of drugs. It has been shown that azole resistance can be reversed by the co-administration of a histone deacetylase (HDAC) inhibitor, suggesting that resistance is mediated by epigenetic mechanisms possibly involving Hos2, a fungal deacetylase. We report here the cloning and functional characterization ofHOS2 (HighOsmolaritySensitive),a gene coding for fungal histone deacetylase fromC. albicans. Inhibition studies showed that Hos2 is susceptible to pan inhibitors such as trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), but is not inhibited by class I inhibitors such MS-275. Purified Hos2 protein consistently deacetylated tubulins, rather than histones from TSA-treated cells. Thisinvitroenzymatic assay, which is amenable to high throughput could be used for screening potent fungal Hos2 inhibitors that could be a potential anti-fungal adjuvant. Hos2 has been reported to be a putative NAD+ dependent histone deacetylase, a feature of sirtuins. We assayed for sirtuin activation with resveratrol and purified Hos2 protein and did not find any sirtuin activity.

scholarly journals Identification, molecular cloning and functional characterization of an octaprenyl pyrophosphate synthase in intra-erythrocytic stages of Plasmodium falciparum

2005 ◽  
Vol 392 (1) ◽  
pp. 117-126 ◽  
Author(s):  
Renata Tonhosolo ◽  
Fabio L. D'Alexandri ◽  
Fernando A. Genta ◽  
Gerhard Wunderlich ◽  
Fabio C. Gozzo ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Recombinant Protein ◽  
Polyclonal Antibodies ◽  
Functional Characterization ◽  
Side Chains ◽  
Reverse Phase ◽  
Novel Drugs ◽  
Michaelis Constants ◽  
Living Organisms

Isoprenoids play important roles in all living organisms as components of structural cholesterol, steroid hormones in mammals, carotenoids in plants, and ubiquinones. Significant differences occur in the length of the isoprenic side chains of ubiquinone between different organisms, suggesting that different enzymes are involved in the synthesis of these side chains. Whereas in Plasmodium falciparum the isoprenic side chains of ubiquinone contain 7–9 isoprenic units, 10-unit side chains are found in humans. In a search for the P. falciparum enzyme responsible for the biosynthesis of isoprenic side chains attached to the benzoquinone ring of ubiquinones, we cloned and expressed a putative polyprenyl synthase. Polyclonal antibodies raised against the corresponding recombinant protein confirmed the presence of the native protein in trophozoite and schizont stages of P. falciparum. The recombinant protein, as well as P. falciparum extracts, showed an octaprenyl pyrophosphate synthase activity, with the formation of a polyisoprenoid with eight isoprenic units, as detected by reverse-phase HPLC and reverse-phase TLC, and confirmed by electrospray ionization and tandem MS analysis. The recombinant and native versions of the enzyme had similar Michaelis constants with the substrates isopentenyl pyrophosphate and farnesyl pyrophosphate. The recombinant enzyme could be competitively inhibited in the presence of the terpene nerolidol. This is the first report that directly demonstrates an octaprenyl pyrophosphate synthase activity in parasitic protozoa. Given the rather low similarity of the P. falciparum enzyme to its human counterpart, decaprenyl pyrophosphate synthase, we suggest that the identified enzyme and its recombinant version could be exploited in the screening of novel drugs.

Characterization of Tamm-Horsfall Urinary Glycoprotein

1973 ◽  
Vol 31 ◽  
pp. 420-421
Author(s):  
John P. Robinson ◽  
J. David Puett
Keyword(s):  
Electron Microscopy ◽  
Circular Dichroism ◽  
Secondary Structure ◽  
Quaternary Structure ◽  
Normal Adult ◽  
Morphological Properties ◽  
Adult Males ◽  
Circular Dichroïsm ◽  
Urinary Glycoprotein

Much work has been reported on the chemical, physical and morphological properties of urinary Tamm-Horsfall glycoprotein (THG). Although it was once reported that cystic fibrotic (CF) individuals had a defective THG, more recent data indicate that THG and CF-THG are similar if not identical.No studies on the conformational aspects have been reported on this glycoprotein using circular dichroism (CD). We examined the secondary structure of THG and derivatives under various conditions and have correlated these results with quaternary structure using electron microscopy.THG was prepared from normal adult males and CF-THG from a 16-year old CF female by the method of Tamm and Horsfall. CF female by the method of Tamm and Horsfall.

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