| 1. |
- Abdurahman, Samir, 1965-, et al.
(författare)
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Activity of the small modified amino acid alpha-hydroxy glycineamide on in vitro and in vivo human immunodeficiency virus type 1 capsid assembly and infectivity
- 2008
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Ingår i: Antimicrobial Agents and Chemotherapy. - 0066-4804 .- 1098-6596. ; 52:10, s. 3737-3744
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Tidskriftsartikel (refereegranskat)abstract
- Upon maturation of the human immunodeficiency virus type 1 (HIV-1) virion, proteolytic cleavage of the Gag precursor protein by the viral protease is followed by morphological changes of the capsid protein p24, which will ultimately transform the virus core from an immature spherical to a mature conical structure. Virion infectivity is critically dependent on the optimal semistability of the capsid cone structure. We have reported earlier that glycineamide (G-NH(2)), when added to the culture medium of infected cells, inhibits HIV-1 replication and that HIV-1 particles with aberrant core structures were formed. Here we show that it is not G-NH(2) itself but a metabolite thereof, alpha-hydroxy-glycineamide (alpha-HGA), that is responsible for the antiviral activity. We show that alpha-HGA inhibits the replication of clinical HIV-1 isolates with acquired resistance to reverse transcriptase and protease inhibitors but has no effect on the replication of any of 10 different RNA and DNA viruses. alpha-HGA affected the ability of the HIV-1 capsid protein to assemble into tubular or core structures in vitro and in vivo, probably by binding to the hinge region between the N- and C-terminal domains of the HIV-1 capsid protein as indicated by matrix-assisted laser desorption ionization-mass spectrometry results. As an antiviral compound, alpha-HGA has an unusually simple structure, a pronounced antiviral specificity, and a novel mechanism of antiviral action. As such, it might prove to be a lead compound for a new class of anti-HIV substances.
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| 2. |
- Abdurahman, Samir, et al.
(författare)
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Anti-HIV activity of the small modified amino acid {alpha}-hydroxy glycineamide on in vitro and in vivo HIV-1 capsid assembly and infectivity
- 2008
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Ingår i: Antimicrobial Agents and Chemotherapy. - 1098-6596. ; 52:10, s. 3737-3744
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Tidskriftsartikel (refereegranskat)abstract
- Upon maturation of the HIV-1 virion, proteolytic cleavage of the Gag precursor protein by the viral protease is followed by morphological changes of the capsid protein p24 which will ultimately transform the virus core from an immature spherical to a mature conical structure. Virion infectivity is critically dependent on the just right semi-stability of the capsid cone structure. We have earlier reported that glycineamide (G-NH2) when added to the culture medium of infected cells inhibits HIV-1 replication and that HIV-1 particles with aberrant core structures were formed. Here we show that it is not G-NH2 itself but a metabolite thereof, alpha-hydroxy-glycineamide (alpha-HGA), that is responsible for the antiviral activity. We show that alpha-HGA inhibits the replication of clinical HIV-1 isolates with acquired resistance to reverse transcriptase and protease inhibitors but has no effect on the replication of any of ten different RNA and DNA viruses. alpha-HGA affected the ability of the HIV-1 capsid protein to assemble into tubular or core structures in vitro and in vivo, probably by binding to the hinge region between the N- and C-terminal domains of the HIV-1 capsid protein as indicated by MALDI-MS results. As an antiviral compound, alpha-HGA has an unusually simple structure, a pronounced antiviral specificity and a novel mechanism of antiviral action. As such, it might prove to be a lead compound for a new class of anti-HIV substances.
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| 3. |
- Abdurahman, Samir, 1965-, et al.
(författare)
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Isolation and characterization of a small antiretroviral molecule affecting HIV-1 capsid morphology
- 2009
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Ingår i: Retrovirology. - : Springer Science and Business Media LLC. - 1742-4690. ; 6, s. 34-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Formation of an HIV-1 particle with a conical core structure is a prerequisite for the subsequent infectivity of the virus particle. We have previously described that glycineamide (G-NH2) when added to the culture medium of infected cells induces non-infectious HIV-1 particles with aberrant core structures. Results: Here we demonstrate that it is not G-NH2 itself but a metabolite thereof that displays antiviral activity. We show that conversion of G-NH2 to its antiviral metabolite is catalyzed by an enzyme present in bovine and porcine but surprisingly not in human serum. Structure determination by NMR suggested that the active G-NH2 metabolite was alpha-hydroxy-glycineamide (alpha-HGA). Chemically synthesized alpha-HGA inhibited HIV-1 replication to the same degree as G-NH2, unlike a number of other synthesized analogues of G-NH2 which had no effect on HIV-1 replication. Comparisons by capillary electrophoresis and HPLC of the metabolite with the chemically synthesized alpha-HGA further confirmed that the antiviral G-NH2-metabolite indeed was alpha-HGA. Conclusion: alpha-HGA has an unusually simple structure and a novel mechanism of antiviral action. Thus, alpha-HGA could be a lead for new antiviral substances belonging to a new class of anti-HIV drugs, i.e. capsid assembly inhibitors.
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| 4. |
- Anderot, Maria, et al.
(författare)
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Determination of dissociation constants between polyelectrolytes and proteins by affinity capillary electrophoresis
- 2009
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Ingår i: Journal of chromatography. B. - : Elsevier BV. - 1570-0232 .- 1873-376X. ; 877:10, s. 892-896
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Tidskriftsartikel (refereegranskat)abstract
- In this manuscript we report the binding affinity between two model proteins, human serum albumin (HSA) and ribonuclease A (RNase A), and negatively charged polyelectrolytes, two different heparin fractions and dextran sulfate, by means of partial filling and affinity capillary electrophoresis. The apparent dissociation constants, K-d, obtained by use of the partial-filling method, between HSA and heparin (17 kDa), heparin (3 kDa) and dextran sulfate (8 kDa) were 33 and 307 mu M, respectively. A new method was developed to determine affinities that take in account different migration directions between the protein and the polyelectrolyte, which was required to study RNase A. By use of this affinity capillary electrophoresis two K-d values were observed for the interaction between RNase A and heparin 17 kDa, yielding a high affinity binding with K-d1 0.0075 mu M, and a lower affinity binding with K-d2 8.7 mu M. For dextran sulfate 8 kDa these K-d values were 0.027 and 10.4 mu M, respectively. Heparin 3 kDa only showed a single K-d value of 0.52 mu M. The results show that the magnitude of the binding affinity depends on the type of polyelectrolyte and its molecular weight. (C) 2009 Elsevier B.V. All rights reserved.
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| 5. |
- Bacskay, Ivett, et al.
(författare)
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Universal method for synthesis of artificial gel antibodies by the imprinting approach combined with a unique electrophoresis technique for detection of minute structural differences of proteins, viruses, and cells (bacteria). III : Gel antibodies against cells (bacteria)
- 2006
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Ingår i: Electrophoresis. - : Wiley. - 0173-0835 .- 1522-2683. ; 27:23, s. 4682-4687
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Tidskriftsartikel (refereegranskat)abstract
- Artificial antibodies in the form of gel granules were synthesized from the monomers acrylamide and N,N'-methylenebisacrylamide by the imprinting method in the presence of Echerichia coli bacteria as template. The electrophoretic migration velocities of the gel antibodies (i) saturated with the antigen (Escherichia coli MRE-600), (ii) freed of the antigen, and (iii) resaturated with bacteria, were determinated by electrophoresis in a rotating narrow-bore tube of 245 mm length and the 2.5 and 9.6 mm inner and outer diameters, respectively. Removal of bacteria from the gel antibodies was made by treatment with enzymes, followed by washing with SDS and buffer. Gel granules becoming charged by adsorption of bacteria move in an electrical field. We obtained a significant selectivity of gel antibodies for E coli MRE-600, since the granules did not interact with Lactococcus lactis; and when E coli BL21 bacteria were added to the gels selective for E coli MRE-600, a significant difference in the migration rate of the complexes formed with the two strains was observed indicating the ability of differentiation between the two strains. The gel antibodies can be used repeatedly. The new imprinting method for the synthesis of artificial gel antibodies against bioparticles described herein, and the classical electrophoretic analysis technique employed, thus represent - when combined - a new approach to distinguish between different types and strains of bacteria. The application area can certainly be extended to cover other classes of cells.
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| 6. |
- Farkas, Viktor, et al.
(författare)
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General approach for certain quantitative calculations for Instance of the variance of reversible adsorption to the capillary wall in CE
- 2009
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 1520-6882 .- 0003-2700. ; 81:1, s. 343-348
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Tidskriftsartikel (refereegranskat)abstract
- Miniaturization of analytical separation methods offers several advantages, including short run times, high resolution, and high recovery of the sample constituents. To optimize these parameters, the reversible adsorption (to minimize loss in resolution), as well as the irreversible adsorption (to minimize loss of analytes) must be quantified. However, no useful equation is available for the calculation of the variance of reversible adsorption. Therefore, we have taken another approach to quantify the reversible interaction. The method is unique and important since no equation for calculation of this variance is required. Instead, two experiments are required, which are run under such conditions that the variance of a certain parameter has the same numerical value in the two experiments (one with and without EOF), except for the variance of reversible adsorption. The approach is universal in the sense that it can be used for many different mathematical concepts and be modified to also cover certain functions other than a sum of parameters. We have also introduced a simple expression for the irreversible adsorption, which shows that the hydrophobic interaction from only two methyl groups in the coating gives rise to as much as 40-50% loss of protein, and the width of the zones in the capillary with this coating was 8-15% larger compared to the zone width in the polyacrylamide-coated capillaries. The reproducibility in migration time, peak area, and peak width in two consecutive runs in capillaries with two methyl groups in the coating was very low, but in EOF-free polyacrylamide-coated capillaries extremely high, indicating that the reversible and irreversible adsorption of proteins to this coating is negligible. The scanning detector, frequently used in free zone electrophoresis in the 1960s-1970s, gives true separation parameters and is, therefore, much preferable to the stationary detector used in most CE experiments, because this detector gives apparent separation parameters.
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| 7. |
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| 8. |
- Gonzalez, Henrik, et al.
(författare)
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Identification of novel candidate protein biomarkers for the post-polio syndrome — Implications for diagnosis, neurodegeneration and neuroinflammation
- 2009
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 71:6, s. 670-681
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Tidskriftsartikel (refereegranskat)abstract
- Survivors of poliomyelitis often develop increased or new symptoms decades after the acute infection, a condition known as post-polio syndrome (PPS). The condition affects 20-60% of previous polio patients, making it one of the most common causes of neurological deficits worldwide. The underlying pathogenesis is not fully understood and accurate diagnosis is not feasible. Herein we investigated whether it was possible to identify proteomic profile aberrations in the cerebrospinal fluid (CSF) of PPS patients. CSF from 15 patients with well-defined PPS were analyzed for protein expression profiles. The results were compared to data obtained from nine healthy controls and 34 patients with other non-inflammatory diseases which served as negative controls. In addition, 17 samples from persons with secondary progressive multiple sclerosis (SPMS) were added as relevant age-matched references for the PPS samples. The CSF of persons with PPS displayed a disease-specific and highly predictive (p=0.0017) differential expression of five distinct proteins: gelsolin, hemopexin, peptidylglycine alpha-amidating monooxygenase, glutathione synthetase and kallikrein 6, respectively, in comparison with the control groups. An independent ELISA confirmed the increase of kallikrein 6. We suggest that these five proteins should be further evaluated as candidate biomarkers for the diagnosis and development of new therapies for PPS patients.
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| 10. |
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