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At least 811 records · Page 45Linked to original sources

PubMed2005

A novel xyloglucan from seeds of Afzelia africana Se. Pers.--extraction, characterization, and conformational properties.

This paper is the first multi-scale characterization of the xyloglucan extracted from seeds of the African tree Afzelia africana Se. Pers. It describes the extraction and characterization of this polysaccharide in terms of both primary monosaccharide and oligosaccharide composition. It also includes a study of the seed morphology. Morphological characterization includes optical, transmission, and scanning electron microscopy. The polysaccharide exists in thickened cell walls of the cotyledonary cells, and the extracted xyloglucan is structurally quite similar to those from tamarind seed and detarium. Nevertheless there are some subtle differences in the fine structure, particularly in the oligomeric xyloglucan composition. The chain flexibility of the polysaccharide is also discussed in the light of our recent measurements reported elsewhere [Biomacromolecules2004, 5, 2384-2391].

Carbohydrate Conformation↗

PubMed2026

Identification and characterization of G protein-coupled receptors in the nocturnal halictid bee Megalopta genalis.

G protein-coupled receptors (GPCRs) are one of the largest families of membrane proteins in insects, regulating vision, neural signal transduction, and various physiological behaviors. Megalopta genalis exhibits a unique facultatively eusocial lifestyle and possesses adaptations for nocturnal activity; however, its GPCR family has not yet been systematically characterized. In this study, we performed genome-wide identification, phylogenetic analysis, and expression profiling of GPCRs in M. genalis by integrating genomic annotation and transcriptomic analysis. The results showed that a total of 99 GPCRs were identified in the genome of M. genalis, which were classified into four major families. Here, we show that M. genalis has undergone lineage-specific GPCR repertoire remodeling, marked by the expansion of novel orphan receptors and the systematic loss of multiple receptor subtypes, such as the neuropeptide receptors MIP-R and NPFR. Moreover, opsins have formed a diverse array of combinations and non-GPCR odorant receptors have undergone significant expansion via tandem duplication. Together, these features may represent part of the molecular repertoire associated with the adaptation of M. genalis to a nocturnal lifestyle. Furthermore, transcriptomic analysis revealed distinct spatiotemporal expression divergence within each of the Mth/Mthl and Fz GPCR families, suggesting functional specialization across development and adult tissues. This study provides the first systematic identification and initial functional characterization of GPCRs in M. genalis, revealing an evolutionary pattern characterized by the coexistence of contraction and expansion within the GPCR family. These findings lay a foundation for further studies aimed at elucidating the roles of these GPCRs in regulating M. genalis physiology and behavior.

Animals↗

PubMed2006

Cloning, characterization and expression analysis of two Tetraodon nigroviridis interleukin-16 isoform genes.

Interleukin-16 (IL-16) is an important pro-inflammatory cytokine that functions as a chemoattractant factor and is well characterized in human and other mammals, but is largely unknown in fish. In the present study, two isoforms of pro-IL-16 homologues were cloned and characterized from pufferfish Tetraodon nigroviridis. The full-length T. nigroviridis pro-IL-16 isoform 1 cDNA exhibits 2453 bp in size including 291 bp 5'UTR (untranslated region), 1704 bp ORF (open reading frame) and 458 bp 3'UTR, while pro-IL-16 isoform 2 cDNA exhibits a 3801 bp ORF and a 458 bp 3'UTR. Bioinformatics analysis demonstrated that the pro-IL-16 isoform 1 with a predicted mass of 60.6 kDa contained two PDZ (postsynaptic density/disc large/zona occludens-1) domains, whereas the 138.2 kDa pro-IL-16 isoform 2 had two additional PDZ domains in its N-terminal extension. RT-PCR results revealed that ,almost in all examined organs and tissues, the mRNA of both pro-IL-16 isoforms can be detected, except in intestine and gill, where the isoform 2 mRNA is absent. The two putative precursor proteins showed 30.0-33.0% identity to various mammalian and avian homologues. This is the first report of such genes in teleostean fish and we hope the molecular characterization of these two pro-IL-16 isoforms will provide insights into the study of both evolution of IL-16 precursor proteins and the immune system as a whole.

Amino Acid Sequence↗

PubMed2004

Development of an analytical reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry method for characterization of recombinant antibodies.

Analytical characterization of monoclonal antibodies has been hindered by the lack of appropriate chromatographic methods to be used in conjunction with high-resolution MS. Current methodologies for standard RP-HPLC are incompatible with antibodies due to irreproducibility, low recovery, short column lifetimes, and poor resolution of degradation products. An analytical RP-HPLC-MS method was developed for monitoring and characterizing intact IgG1antibodies. Key parameters required for improved chromatographic resolution included long alkyl chains of the stationary phase (Zorbax SB300 C8), column temperatures elevated to 65-70 degrees C and combination of trifluoroacetic acid and heptafluorobutyric acid ion-pairing agents. RP chromatographic separation of degradation species and C-terminal lysine variants along with the characterization of glycosylation profile by mass spectrometry demonstrates the capability of this method for whole antibody analysis.

Antibodies↗

PubMed2005

Characterization of waxes used in pictorial artworks according to their relative amount of fatty acids and hydrocarbons by gas chromatography.

A study attempted to characterize natural waxes used in pictorial works of art was carried out by means of gas chromatography. The analytical treatment requires prior hydrolysis of the waxes to release the fatty acids (FA) (myristic (myr), palmitic (pal), oleic (ole), stearic (ste), araquidic (ara), behenic (beh), lignoceric (lig), cerotic (cer)) from the main esters of the waxes. The formation of volatile derivatives of the fatty acids was carried out by derivatization with ethyl choroformate (ECF). This derivatization reagent was chosen due to the speed, safety and quantitativity of the reaction. The analyzed hydrocarbons were n-eicosane, n-heneicosane, n-docosane, n-tricosane, n-tetracosane, n-pentacosane, n-hexacosane, n-heptacosane, n-octacosane, n-nonacosane, n-tricontane n-hentriacontane, n-dotriacontane, n-tritriacontane, n-tetratriacontane, n-pentatriacontane, main constituents of the waxes. No derivatization is needed to analyze the hydrocarbons. Ethyl ester derivatives and hydrocarbons are adequately separated by gas chromatography, identified by flame ionization detection and confirmed by mass spectrometry. To characterize natural waxes, peak area ratios of each fatty acids with respect to the palmitic acid and peak area ratios of each hydrocarbons with respect to n-heptacosane were calculated. The proposed method provides a good characterization of different waxes most frequently used in artworks, such as beeswax, carnauba wax and ceresin, and has been successfully applied to real samples. This is the first report on the application of ECF to the analysis of fatty acids in wax.

Chromatography, Gas↗

PubMed2006

Characterization of quantum dot bioconjugates by capillary electrophoresis with laser-induced fluorescent detection.

In this paper, we present a universal, highly efficient and sensitive method for the characterization of quantum dot (QD) bioconjugates based on capillary electrophoresis with laser-induced fluorescent (LIF) detection. We first prepared CdTe QDs in aqueous phase by a chemical route with mercaptopropionic acid as a ligand, and then were coupled to certain proteins using bifunctional linkage reagent or electrostatic attraction. The QD bioconjugates were characterized by capillary electrophoresis with LIF detection. We found that QD bioconjugates were efficiently separated with free QDs by the optimization of buffer pH. Furthermore, we found that ultrafiltration was an effective and simple approach to purify QD conjugates with bovine serum albumin (BSA). Due to their broad absorption spectra and size dependent emission wavelength tunability, QDs can be excited to emit different colour fluorescence using a single wavelength laser source, and therefore, we believe that CE with LIF detection will become a universal and efficient tool for the characterization of QD bioconjugates.

Electrophoresis, Capillary↗

PubMed2006

Identification, characterization and quantitation of pyrogenic polycylic aromatic hydrocarbons and other organic compounds in tire fire products.

On 15 August 2001, a tire fire took place at the Pneu Lavoie Facility in Gatineau, Quebec, in which 4000 to 6000 new and recycled tires were stored along with other potentially hazardous materials. Comprehensive gas chromatography-mass spectrometry (GC-MS) analyses were performed on the tire fire samples to facilitate detailed chemical composition characterization of toxic polycyclic aromatic hydrocarbons (PAHs) and other organic compounds in samples. It is found that significant amounts of PAHs, particularly the high-ring-number PAHs, were generated during the fire. In total, 165 PAH compounds including 13 isomers of molecular weight (MW) 302, 10 isomers of MW 278, 10 isomers of MW 276, 7 isomers of MW 252, 7 isomers of MW 228, and 8 isomers of MW 216 PAHs were positively identified in the tire fire wipe samples for the first time. Numerous S-, O-, and N-containing PAH compounds were also detected. The identification and characterization of the PAH isomers was mainly based on: (1) a positive match of mass spectral data of the PAH isomers with the NIST authentic mass spectra database; (2) a positive match of the GC retention indices (I) of PAHs with authentic standards and with those reported in the literature; (3) agreement of the PAH elution order with the NIST (US National Institute of Standards and Technology) Standard Reference Material 1597 for complex mixture of PAHs from coal tar; (4) a positive match of the distribution patterns of PAH isomers in the SIM mode between the tire fire samples and the NIST Standard Reference Materials and well-characterized reference oils. Quantitation of target PAHs was done on the GC-MS in the selected ion monitoring (SIM) mode using the internal standard method. The relative response factors (RRF) for target PAHs were obtained from analyses of authentic PAH standard compounds. Alkylated PAH homologues were quantitated using straight baseline integration of each level of alkylation.

Automobiles↗

PubMed2006

On-line size exclusion chromatography-pyrolysis-gas chromatography-mass spectrometry for copolymer characterization and additive analysis.

On-line coupled size exclusion chromatography-pyrolysis gas chromatography mass spectrometry (SEC-Py-GC-MS) is studied as a novel tool for the characterization of complex polymer samples. An automated system for on-line SEC-Py-GC-MS allowing transfer of multiple fractions was developed based on stop-flow operation of the SEC dimension, syringe-based transfer of the SEC fraction to the GC instrument and solvent elimination with subsequent pyrolysis in a programmed temperature vaporization (PTV) injector. After optimization the system was applied to the characterization of a complex terpolymer composed of very similar monomers. The use of the system for combined pyrolysis and additive analyses in polycarbonate was also demonstrated. Results obtained with the new method indicate the interesting potentials of the method for detailed characterization of polymeric materials.

Chromatography, Gel↗

PubMedDate not supplied

Computed tomography angiography in detection and characterization of ruptured anterior cerebral artery aneurysms at uncommon location for emergent surgical clipping.

INTRODUCTION: Cerebral subarachnoid hemorrhage may result from rupture of saccular aneurysms at uncommon location [excluding the anterior communicating artery (ACOM)] of the anterior cerebral artery (ACA). The purpose of this study was to evaluate the usefulness of helical computed tomography angiography (CTA) in detection and characterization of intracranial aneurysms at such uncommon locations before emergent surgical clipping. MATERIALS AND METHODS: Between 1998 and 2003, records for 50 consecutive patients who underwent emergent surgical clipping for intracranial aneurysms were reviewed. Eighteen of these patients had aneurysms in the ACA. After those patients with unequivocal ACOM aneurysms were excluded, eight patients with eight aneurysms in an uncommon location of the ACA were recruited to this study. Plain computed tomography (CT) and CTA were performed in eight patients, and digital subtraction angiographies were done in three patients. Each aneurysm was evaluated for the detection, quantification, and characterization of the aneurysms with 2D multiplanar reformatted and 3D volume-rendering techniques. RESULTS: There were two small aneurysms arising from the A1 segment, one from the A2 segment, two at the junction of triplicated ACAs, two at the junction of A2 and A3 segments, and one at the junction of A2 and A3 segments of the azygos ACA. The average diameter of the aneurysmal sac was 4.44 mm (range, 2.7-7.0 mm), and the aneurysmal neck averaged 2.59 mm (range, 1.2-3.5 mm) in size. The smallest aneurysm measured 2.2x1.8x2.7 mm (neck, 1.2 mm) in the A1 segment of the left ACA. Three patients had intracerebral hematoma, seven had intraventricular hemorrhage, and three had acute hydrocephalus. CONCLUSION: Aneurysms in uncommon locations of ACAs exhibited characteristic features. Rupture of these aneurysms can cause intracerebral hematoma, intraventricular hemorrhage, and/or acute hydrocephalus. Noninvasive CTA can reliably detect and characterize intracranial aneurysms at such uncommon location for planning of emergent surgical intervention.

Adult↗

PubMed2005

Characterization of glycans on major histocompatibility complex class II molecules in channel catfish, Ictalurus punctatus.

The glycans associated with mammalian major histocompatibility complex (MHC) class II molecules have been studied extensively. Co-translational and post-translational addition of sugar molecules to proteins confers many structural and modulatory functions. In the present study we characterized the glycans associated with MHC class II molecules in the channel catfish to compare glycosylation patterns in a teleost to those known to occur in mammals. This study made use of enzymatic methods and two-dimensional (2D) gel electrophoresis to characterize the N-linked sugars. Unlike mammalian T cells which expressed complex N-linked sugars, channel catfish derived 28S T cells were found to express high-mannose/hybrid N-glycans on class II molecules. However studies with Endoglycosidase H in conjunction with cell surface labeling on peripheral blood leukocytes revealed that catfish possess the machinery to modify the intermediate high-mannose sugars to complex type sugars. Nonetheless, the majority of the class II cell surface glycoproteins were of the high-mannose type. Resolution of catfish MHC class II molecules by 2D gel analyses revealed multiple bands for class II beta chains whereas class II alpha chains focused as a single spot. Glycosylation in the channel catfish, a premier model system for studying the immune system of teleosts, has significant differences from the glycosylation patterns characterized in mammalian systems, likely with functional implications.

Animals↗

PubMed2006

Physical properties and microstructural characterization of dental porcelains mixed with distilled water and modeling liquid.

OBJECTIVE: The aim of this study was to microstructurally characterize and to make comparisons of the physical properties of sintered dental porcelains prepared by mixing with distilled water and with their modeling liquid. METHODS: Six commercial porcelain powders: IPS Classic (Ivoclar Vivadent AG, Schaan, Liechtenstein), IPS d.SIGN (Ivoclar Vivadent AG), IPS InLine (Ivoclar Vivadent AG), Vita VMK95 (Vita Zahnfabrik, Bad Sackingen, Germany), Vita OMEGA 900 (Vita) and Ceramco III (Ceramco-Dentsply, Burlington, NJ, USA) were used as starting powders. Following particle size and BET analyses of starting powders, each porcelain powder was mixed with distilled water and with its own modeling liquid. Disc specimens were sintered in accordance with each manufacturer's instructions. Specimens were characterized using X-ray diffraction (XRD), optical microscopy and SEM analysis and their physical properties such as bulk density, microhardness and biaxial flexural strength were determined. RESULTS: The sintered dental porcelains premixed with modeling liquid had density, biaxial flexural strength and microhardness values slightly higher than those premixed with distilled water. Mixing with distilled water and modeling liquid caused statistically significant differences between the density values of Vita VMK 95 and microhardness values of IPS d.SIGN and IPS InLine. Characterization investigations (XRD and SEM) revealed the coexistence of the tetragonal leucite (1-3 microm) and hexagonal fluorapatite crystals (0.4-1.2 microm) in a feldspathic glassy matrix in the microstructure of IPS d.SIGN and only leucite crystals (3-6 microm) in the microstructures of other porcelains. SIGNIFICANCE: Mixing the porcelain powders with distilled water or modeling liquid prior to sintering has no effect on the resultant sintered crystalline microstructure. On the other hand, significant differences exist between the physical properties of some porcelains.

Aluminum Silicates↗

PubMed2005

Biochemical characterization of the RECQ4 protein, mutated in Rothmund-Thomson syndrome.

Rothmund-Thomson syndrome (RTS) is an autosomal recessive disorder characterized by growth deficiency, skin and skeletal abnormalities, and a predisposition to cancer. Mutations in the RECQ4 gene, one of five human homologs of the E. coli recQ gene, have been identified in a subset of RTS patients. Cells derived from RTS patients show high levels of chromosomal instability, implicating this protein in the maintenance of genomic integrity. However, RECQ4 is the least characterized of the RecQ helicase family with regard to its molecular and catalytic properties. We have expressed the human RECQ4 protein in E. coli and purified it to near homogeneity. We show that RECQ4 has an ATPase function that is activated by DNA, with ssDNA being much more effective than dsDNA in this regard. We have determined that a DNA length of 60 nucleotides is required to maximally activate ATP hydrolysis by RECQ4, while the minimal site size for ssDNA binding by RECQ4 is between 20 and 40 nucleotides. Interestingly, RECQ4 possesses a single-strand DNA annealing activity that is inhibited by the single-strand DNA binding protein RPA. Unlike the previously characterized members of the RecQ family, RECQ4 lacks a detectable DNA helicase activity.

Adenosine Triphosphatases↗

PubMed2006

Designing novel pH-sensitive non-phospholipid vesicle: characterization and cell interaction.

In this work, we report the preparation, the characterization and interaction with cells of novel pH-sensitive non-phospholipid vesicle formulations, from a non-ionic surfactant mixed with cholesterol (CHOL) and his derivative cholesteryl hemisuccinate (CHEMS), as pH-sensitive molecule. This molecule, can destabilize the vesicle lipid bilayer when exposed to an acidic environment, with a subsequent release of vesicular content, enhancing the cytoplasmatic delivery of drugs to target cells. Vesicles were characterized by static and dynamic light scattering, in order to evaluate their dimensions, bilayer thickness and vesicle stability. Membrane permeability changes were determined by the release of entrapped hydroxypyrene-1,3,6-trisulfonic acid (HPTS). Also diphenylhesatriene (DPH) fluorescence anisotropy and zeta potential measurements were used to evidence the pH sensitivity. Furthermore vesicles were characterized by means of electronic microscopy after freeze-fracture. The interaction of non-lipid vesicles containing different fluorescent dyes with Raw 264.7, mouse monocite macrophage, were analyzed by flow cytometric analysis. The obtained results indicate that the pH-sensitive vesicular structures show good plasma stability and relevant pH-sensitivity. Moreover this formulation was able to interact with target membranes (i.e. plasma or endosomal membrane) and to release the encapsulated material into the cytoplasm.

Animals↗

PubMed2006

Improved spatial characterization of the epileptic brain by focusing on nonlinearity.

An advanced characterization of the complicated dynamical system brain is one of science's biggest challenges. Nonlinear time series analysis allows characterizing nonlinear dynamical systems in which low-dimensional nonlinearity gives rise to complex and irregular behavior. While several studies indicate that nonlinear methods can extract valuable information from neuronal dynamics, others doubt their necessity and conjecture that the same information can be obtained using classical linear techniques. To address this issue, we compared these two concepts, but included furthermore a combination of nonlinear measures with surrogates, an approach that has been designed to specifically focus on nonlinearity. As a benchmark we used the discriminative power to detect the seizure-generating hemisphere in medically intractable mesial temporal lobe epilepsy. We analyzed intracranial electroencephalographic recordings from the seizure-free interval of 29 patients. While the performance of both linear and nonlinear measures was weak, if not insignificant, a very high performance was obtained by the use of surrogate-corrected measures. Focusing on nonlinearity by using a combination of nonlinear measures with surrogates appears as the key to a successful characterization of the spatial distribution of the epileptic process.

Electroencephalography↗

PubMed2005

Characterization of complex mixtures in urban atmospheres for inhalation exposure studies.

A real-world assessment of the source-to-receptor pathways for ambient particulate matter (PM), as opposed to in a laboratory environment, was crucial for gaining a better understanding of the types of particles to which people are actually exposed in their daily lives, and of the human-health risks for source-specific PM. However, obtaining scientific evidence linking specific source emissions to health responses was not an easy task; ambient PM possesses diverse chemical, physical and thermodynamic properties, and is subjected to numerous complex atmospheric processes in which source type, source strength, sinks, and meteorology interact continuously. Our collaborative PM health research studies utilized an integrated approach that employs detailed characterization of ambient PM concurrent with inhalation toxicology studies using animal models and concentrated fine air particulates (CAPs). Ambient PM2.5 (PM less than 2.5 microm in mean aerodynamic diameter) was concentrated with a Harvard fine particle concentrator housed in AirCARE1, a unique mobile air research laboratory which enables inhalation exposure studies in real-world settings. This paper discusses the importance of comprehensive characterization of ambient PM2.5, CAPs and their sources, and the associated challenges. In a southwest Detroit community where the pediatric asthma rate is about three times the national average, a detailed assessment was performed including: characterization of ambient PM2.5 and CAPs; identification of major emission sources of PM2.5; and quantification of trace elements in lung tissues of laboratory rats that were exposed to CAPs, all in an effort to define source-receptor pathways for ambient PM2.5. Our findings to date constitute evidence of the retention of ambient urban particulates from local combustion sources within animal tissues from short-term exposures, and possible associations between the observed health effects and source-specific PM2.5. However, a complete understanding of the effects of complex mixtures of air pollutants and their toxicological impacts still faces many challenges.

Air Pollutants↗

PubMed2004

Characterization of beta amyloid assemblies in drusen: the deposits associated with aging and age-related macular degeneration.

PURPOSE: Recent studies strongly suggest that drusen, the extracellular deposits associated with age-related macular degeneration (AMD), are a manifestation of local inflammatory events. New evidence indicates that substructural elements within drusen contain activated complement components as well as amyloid beta (Abeta), a major pro-inflammatory component of Alzheimer's disease plaques. We characterized the ultrastructural organization and histochemical staining properties of these Abeta-containing elements in order to further assess their significance in drusen formation and AMD pathogenesis. METHODS: We used differential interference contrast optics, laser scanning confocal immunofluorescence, and immunogold electron microscopy to characterize the structural properties and molecular composition of Abeta-containing elements in drusen. We obtained estimates of their frequency from montages of electron micrographs gathered from 152 human donor eyes ranging from 9 to 91 years of age. RESULTS: Spherical Abeta-containing elements, which are typically organized as concentric ring-like structures, are common substructural components of drusen. They stain with thioflavin T, but are not stained by Congo red; nor do they bind cationic, lipophilic, or nucleic acid-binding fluorescent dyes. Ultrastructurally, they are composed of a central core, one or more concentric inner rings with intervening electron lucent layers, and an electron dense outer shell. Immunogold labeling indicates that most Abeta immunoreactivity is associated with the outer layers that consist of densely-packed spherical subunits. No longitudinally-oriented fibril arrays, characteristic of aggregated amyloid fibrils in the brain, are evident. Other prominent drusen-associated proteins including the terminal complement complex C5b-9, vitronectin, apolipoprotein E, serum amyloid P component, and ubiquitin are excluded from the spheres.Conclusions. These structures embedded in drusen appear to represent a new type of macromolecular assembly that contains Abeta as well as activated complement components. The presence of Abeta in these extracellular deposits is an additional indication that some of the pathogenic pathways that give rise to drusen and AMD may be shared with other neurodegenerative diseases characterized by misfolded protein deposition and aggregation.

Adolescent↗

PubMed2004

Characterization of a peptide adduct formed by N-acetoxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a reactive intermediate of the food carcinogen PhIP.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a member of a class of compounds known as the heterocyclic amines (HCAs) that are formed in meat during cooking. It is a multi-organ carcinogen in rodents forms adducts and with DNA and protein. Although protein adducts are not thought to be involved in cancer development, they may be useful as internal dosimeters of PhIP exposure and bioactivation. Towards the goals of characterizing the adducts formed in humans and the development of an assay for quantitation of adduct levels, we have characterized a peptide adduct formed by the putative genotoxic metabolite, N-acetoxy-PhIP. A model peptide with the internal sequence Leu-Gln-Lys-Cys-Pro-Tyr, which is homologous to a potential target sequence for HCAs in human serum albumin, was reacted with N-acetoxy-PhIP and an adduct was identified and further characterized by LC-ESI-MS/MS. N-acetoxy-PhIP is covalently bound to the peptide via cysteine and the exocyclic amino group of PhIP. Future work is needed to establish if this adduct is formed and is stable in vivo in humans following exposure to PhIP.

Carcinogens↗

PubMed2006

Expression and functional characterization of ABCG1 splice variant ABCG1(666).

The ATP-binding cassette transporter ABCG1 mediates the transport of excess cholesterol from macrophages and other cell types to high density lipoprotein (HDL) but not to lipid-depleted apolipoprotein AI. Several splice variants which may have different functions have been identified in mammals. In the current study, we characterized the human splice variant ABCG1(666), which differs from full-length ABCG1(678) by absence of an internal segment of 12 amino acids (VKQTKRLKGLRK). Accordingly spliced ABCG1 transcripts were detected in macrophages and liver in approximately twofold higher amounts than the alternatively spliced ABCG1 form encoding full-length ABCG1. We used transient and stable expression of ABCG1(666) fusion proteins to characterize glycosylation, subcellular localization, molecular interaction and functions of this ABCG1 variant. It could be demonstrated that ABCG1(666) is located at the cell surface and has the ability to form cholesterol transport competent homodimers which affect cellular cholesterol export in a similar manner as previously characterized forms of ABCG1. Our results support that ABCG1(666) may in fact be the most prominent form of functional ABCG1 expressed in the human.

ATP Binding Cassette Transporter, Subfamily G, Mem↗