Design and synthesis of a TICT-based red-emissive fluorescent probe for the rapid and selective detection of HSA in human biofluids and live cell imaging

Here, we report the design and synthesis of a D⋯π⋯A-based fluorescent probe, (E)-4-(4-(dibutylamine)-2-hydroxystyryl)-1-methylquinolin-1-ium (DHMQ), which is nonfluorescent in ∼100% PBS buffer medium due to a twisted intra molecular charge transfer (TICT) phenomenon and it becomes highly fluorescent (∼149 fold) in the presence of human serum albumin (HSA), owing to the restriction of its intramolecular free rotation inside the hydrophobic binding cavity of HSA. The site-selective fluorescence displacement assay and molecular docking studies clearly reveal that DHMQ selectively binds at subdomain IB of HSA. The 3σ/slope method was adopted to determine the limit of detection (LOD) value, which was as low as 2.39 nM in ∼100% PBS medium, indicating its high sensitivity towards HSA. The low dissociation constant value [Kd = (1.066 ± 0.017) μM] suggests a strong complexation between the DHMQ and HSA. Importantly, it has been demonstrated that DHMQ is capable of detecting HSA in real human serum and urine samples and was found to be suitable for live cell imaging of HSA.

A novel target and biomarker benzothiazolyl-naphthalimide probes for precisely and selective detection of serum albumin and anticancer activity

N-Benzothiazolyl-1,8-naphthalimide based fluorescence probes were designed and synthesized for selective detection of human serum albumin (HSA) and Bovine serum albumin (BSA) among various bioanalytes and further studied for their in...

Human serum albumin variants in China: a molecular epidemiological investigation and literature review

Background

Bisalbuminemia is a hereditary and/or acquired abnormality characterized by a double albumin (ALB) band on serum protein electrophoresis. However, there have been no epidemiological investigations of ALB variants in Chinese populations.

Methods

This retrospective study examined 71,963 unrelated subjects from five provinces in southern China. ALB variants were screened by cellulose acetate electrophoresis at pH 8.6 and ALB mutations were confirmed by polymerase chain reaction-DNA sequencing.

Results

The average incidence of inherited bisalbuminemia in the southern Chinese population was 0.0264% (19/71,963). Thirteen cases showed slow and six showed fast genetic variants on cellulose acetate electrophoresis. Four kinds of ALB variants were identified: proalbumin Lille (p.Arg23His), ALB Castel di Sangro (p.Lys560Glu), ALB Fukuoka-1 (p.Asp587Asn), and a novel ALB Wuxi (p.Lys562Glu). The gene frequency of ALB variants in the Wuxi region (0.126%, 13/10,297) was significantly higher than in other regions in southern China, and 90.9% (10/11) of cases of proalbumin Lille were also found in the Wuxi region.

Conclusions

This study provides the first report of the detailed prevalence and molecular characterization of ALB variants in southern China. Compared with other areas of China, Wuxi had a different pattern of ALB variants and a high prevalence of proalbumin Lille.

A DS2-specific flavonoid-based probe with a unique dual-emissive response to human serum albumin

The hydroxyl substituent in flavonoids can cause the binding site to change from DS1 to DS2 and restore the ESIPT process of flavonoids, thereby leading to a unique dual-emissive response towards human serum albumin.

Detection of hereditary bisalbuminemia in bottlenose dolphins (Tursiops truncatus, Montagu 1821): comparison between capillary zone and agarose gel electrophoresis

Background

Hereditary bisalbuminemia is a relatively rare anomaly characterized by the occurrence of two albumin fractions on serum protein separation by electrophoresis. In human medicine, it is usually revealed by chance, is not been clearly associated with a specific disease and the causative genetic alteration is a point mutation of human serum albumin gene inherited in an autosomal codominant pattern. This type of alteration is well recognizable by capillary zone electrophoresis (CZE), whilst agarose gel electrophoresis (AGE) not always produces a clear separation of albumin fractions. The aims of this study is to report the presence of this abnormality in two separate groups of related bottlenose dolphins and to compare the results obtained with capillary zone and agarose gel electrophoresis.

Results

Serum samples from 40 bottlenose dolphins kept under human care were analyzed. In 9 samples a double albumin peak was evident in CZE electrophoresis while no double peak was noted in AGE profile. Since only an apparently wider albumin peaks were noted in some AGE electrophoretic profiles, the ratio between base and height (b/h) of the albumin peak was calculated and each point-value recorded in the whole set of data was used to calculate a receiver operating characteristic curve: when the b/h ratio of albumin peak was equal or higher than 0.25, the sensitivity and specificity of AGE to detect bisalbuminemic samples were 87 and 63 %, respectively. The bisalbuminemic dolphins belong to two distinct families: in the first family, all the siblings derived from the same normal sire were bisalbuminemic, whereas in the second family bisalbuminemia was present in a sire and in two out of three siblings.

Conclusions

We report for the first time the presence of hereditary bisalbuminemia in two groups of related bottlenose dolphins identified by means of CZE and we confirm that AGE could fail in the identification of this alteration.

False bisalbuminemia and hyperalphafetoproteinemia

The capillary electrophoresis is a very powerful separation method offering a high degree of resolution. However, certain interferences can be detected giving transitory shoulders or peaks. We report the case of a serum protein electrophoresis performed with Capillarys (Sebia) in a 68-year-old patient, hospitalized for cancer of the head of the pancreas, which showed an important shoulder in the migratory range of albumin, simulating bisalbuminemia. An interference with alphafetoprotein was proven explaining this electrophoretic aspect.

Advances in Serum Protein Electrophoresis

A major advance in serum protein electrophoresis in the last decade has been the introduction of capillary zone electrophoresis (CZE). Two dedicated automated multichannel instruments for serum protein separation by CZE in clinical laboratories are available, the Paragon CZE 2000 (Beckman Coulter, CA) and the Capillarys (Sebia, France). This chapter focuses on the performance of these commercial multichannel CZE systems. Following topics are addressed: precision, comparison of CZE with gel-based methods, dysproteinemia analysis by CZE, detection and identification of monoclonal proteins by CZE, quality control, and interferences. Examples of electrophoretic patterns are given.

Improved resolution of serum bisalbumin on electrophoresis and investigation of bisalbumin in urine

OBJECTIVES

: The aims of this study were to improve the resolution of albumin variants (bisalbumins, especially albumin Naskapi) from albumin in commercial serum protein electrophoresis systems; to compare the separation of bisalbumin from albumin on these improved methods against the recognized gold standard of capillary electrophoresis; and to investigate the presence of albumin variants in urine.

DESIGN AND METHODS

: Electrophoresis was performed using the Sebia Hydrasys 15/30 beta1beta2 system, as well as modified methods on the Sebia Hydrasys HR and the Beckman Paragon systems. The interpretation of electrophoretic gels was performed by manual visualization and densitometric scanning. Serum samples were also analyzed using capillary electrophoresis at Sebia Electrophoresé located in Paris, France. Urine samples were concentrated using Vivaproducts concentration tubes and were electrophoresed using the Sebia Hydrasys HR system.

RESULTS

: Representative gels and scans of serum samples demonstrate the improved resolution of modified electrophoresis methods compared to routine methods. The raw data from the gels and scans were compiled to calculate concordance and discordance for each method.

DISCUSSION

: The various commercial serum protein electrophoresis systems showed improved resolution using the modified methods. In comparison with capillary electrophoresis, the modified Sebia Hydrasys HR and Beckman Paragon methods using visualization demonstrated 100% concordance and thus performed equally as well as the gold standard. Urine studies found that variant albumins are also excreted in the urine in the same 50-50 ratio as that found in the serum.

Automated Multicapillary Electrophoresis for Analysis of Human Serum Proteins

Background: We evaluated a new, automated multicapillary zone electrophoresis (CE) instrument (Capillarys®, 4.51 software version; Sebia) for human serum protein analysis.

Methods: With the Capillarys β1-β2+® reagent set, proteins were separated at 7 kV for 4 min in 15.5 cm × 25 μm fused-silica capillaries (n = 8) at 35.5 °C in a pH 10 buffer with online detection at 200 nm. Serum samples with different electrophoretic patterns (n = 265) or potential interference (n = 69) were analyzed and compared with agarose gel electrophoresis (AGE; Hydrasys®-Hyrys®, Hydragel protein(e) 15/30® reagent set; Sebia).

Results: CVs were <3.5% for albumin, <11% for α1-globulin, <4.1% for α2-globulin, <7.4% for β-globulin, and <5.8% for γ-globulin (3 control levels); measured throughput was 60 samples/h. In patients without paraprotein (n = 116), the median differences between CE and AGE were −5.4 g/L for albumin, 4.0 g/L for α1-globulin, 0.7 g/L for α2-globulin, 0.6 g/L for β-globulin (P <0.001 for all fractions), and −0.1 g/L for γ-globulin (not significant). More samples had at least one γ-migrating peak detected by CE (n = 135 vs 130; paraprotein detection limit, ∼0.5–0.7 g/L), but fewer were quantified (n = 84 vs 91) because of γ- to β-migration shifts. There was a 1.2 g/L median difference between CE and AGE for γ-migrating paraprotein quantification (n = 69; P <0.001). Several ultraviolet-absorbing substances (lipid emulsion, hemoglobin) or molecules (contrast agent, gelatin-based plasma substitute) induced CE artifacts.

Conclusions:The Capillarys instrument is a reliable CE system for serum protein analysis, combining advantages of full automation (ease of use, bar-code identification, computer-assisted correction of α1-globulins) with high analytical performances and throughput.

Separation of serum proteins by automated capillary zone electrophoresis

Capillary zone electrophoresis (CZE) of serum proteins is increasingly gaining impact in clinical laboratories. Two automated multichannel instruments dedicated to the separation of serum proteins have become available over the last 6 years, the Paragon CZE 2000 (Beckman Coulter, CA, USA) and, more recently, the Capillarys (Sebia, France). This review focuses on the performance of these commercial instruments to separate serum proteins in a clinical laboratory setting. The utility of CZE to recognize various dysproteinemias and to detect and identify monoclonal proteins will be described and systematically reviewed. The reader will be provided with a summation and an understanding of CZE-specific interference.

Advances ofcapillary electrophoresis in clinical and forensic analysis (1999-2000)

In this paper, capillary electrophoresis in clinical and forensic analysis is reviewed on the basis of the literature of 1999, 2000 and the first papers in 2001. An overview of progress relevant examples for each major field of application, namely (i) analysis of drug seizures, explosives residues, gunshot residues and inks, (ii) monitoring of drugs, endogenous small molecules and ions in biofluids and tissues, (iii) general screening for serum proteins and analysis of specific proteins (carbohydrate deficient transferrin, alpha1-antitrypsin, lipoproteins and hemoglobins) in biological fluids, and (iv) analysis of nucleic acids and oligonucleotides in biological samples, including oligonucleotide therapeutics, are presented.