Bradford protein assay

About: Bradford protein assay is a research topic. Over the lifetime, 635 publications have been published within this topic receiving 239107 citations.

Analytical performance of the Genzyme LipoPro Lp(a) kit for plasma lipoprotein(a)-cholesterol assay.

Abstract: The analytical performance of a new assay for plasma lipoprotein(a)-cholesterol (Lp[a]-C) was compared with that of our existing Lp(a) protein assay. The Lp(a)-C assay utilises lectin affinity chromatography to isolate intact Lp(a) particles. The effect of apo(a) isoform size on this system was assessed and found to be negligible. Plasma Lp(a) concentrations measured by both assays were in excellent accord in 24 subjects with Lp(a) protein concentrations ranging from 1-65 mg/dL (r2 = 0.916). Linearity of the Lp(a)-C assay system was excellent (r2 = 0.997) and within-run precision was 6.9% at an Lp(a)-C concentration of 0.3 mmol/L. Between-calibration precision was checked and proved to be 7.9%. The lectin-binding reagent used in the assay bound different sized apo(a) isoforms equally, and the recovery of Lp(a) from the reagent was, on average, 64%. We conclude that the Lp(a)-C assay system performs well but that further information is required on what new information, if any, the assay provides over traditional Lp(a) protein measurements by enzyme-linked immunosorbent assay (ELISA) or immunoturbidimetry.

Isolation and Characterization of Silaffin that Catalyze Biosilica Formation from Marine Diatom Chaetoceros gracilis

Abstract: The method of making silica in industries requires extreme conditions. The finding of proteins involved in the formation of biosilica from diatoms, has opened up an alternative way of production. Chaetoceros gracilis is one of the diatoms, which is potential in producing silaffin protein. This study aimed to isolate and to characterize the protein. We also analyzed the protein activity toward tetraethoxyorthosilicate (TEOS) substrate in in vitro reaction. Diatom biomass was harvested and further kept in 2% SDS/100 mM EDTA solution. Protein isolation was conducted by dissolving the silica and separating the protein by soaking in 2 M HF/8 M NH4F. Protein concentration was analyzed using Bradford method and the molecular weight was estimated through SDS-PAGE. Protein activity was observed by reacting it with TEOS substrate to form silica polymer and measured by colorimetric molibdate assay. Protein concentration was 1.20 mg/ml and appeared filamentous. The apparent molecular weights consisted of 12, 23, 42, 44 kDa. These protein was able to polymerize the silica at room temperature within 10 min. As much as 85.65 umol TEOS was polymerized per 1.4 x 106 silaffin protein per min. SEM analysis showed the formation of spherical, aggregate biosilica. Key words: Chaetoceros gracilis, silaffin protein, biosilica, polymerization

Comparison study of therapeutic properties of proteins and secondary metabolites from carica papaya

Abstract: Objective: The current study aims to compare the therapeutic potential of protein extracts and secondary metabolites extracts using methanol, ethyl acetate and hexane from both the fruits and seeds of Carica papaya . Methods: All of the crude proteins and secondary metabolite fractions extracted from the fruits and seeds of Carica papaya were assessed and compared in DPPH free-radical scavenging assay for antioxidant activities and brine shrimp lethality assay for cytotoxic potentials. Protein content was quantified by Bradford assay while total phenolic and flavonoids contents were determined by Folin-Ciocalteu and aluminum chloride colorimetric methods accordingly. Bioactive protein molecules and secondary metabolite fractions were then characterized and analyzed in SDS-PAGE and silica thin layer chromatography respectively. Results: Evidence demonstrated that the secondary metabolite extracts of ethyl acetate fraction of the seeds of Carica papaya have the highest antioxidant activity (IC 50 value of 25.97 µg/ml) as well as cytotoxicity activity (LC 50 value of 142.27 µg/ml) in comparison to other crude proteins, methanol or hexane extracts. Notably, crude protein from fruits possesses relatively high antioxidant (IC 50 value of 34.62 µg/ml) and cytotoxicity (LC 50 value of 222.52 µg/ml) activities. The presence of bioactive phenolic and flavonoid in crude secondary metabolite extracts and bioactive protein molecules in crude protein extracts confer the high antioxidant capacity and cytotoxic potential of Carica papaya . Conclusion: This study proved that the crude protein from fruits and ethyl acetate fraction from seeds and fruits of Carica papaya have great potential to be further developed into therapeutic drugs in future. Keywords: Carica papaya , Antioxidant, Cytotoxicity, Crude fruit protein, Phenolic, Flavonoid

Determination of surface hydrophobicity of milk proteins. Comparison between a new detergent binding method and hydrophobic interaction-FPLC

Abstract: A previously published method for the determination of the surface hydrophobicity of proteins using BIO-RAD protein assay combined with Tween 80 was adopted to various milk proteins. The relative retention times obtained by HI-FPLC at Phenyl-Superose for casein and whey protein were compared with results of the proposed method and expanded by the average hydrophobicity calculated according to BIGELOW. Detergent binding showed good correlation with calculated average hydrophobicities for all milk proteins, whereas HI-FPLC results were found to be accurate only for caseins. The relative order of hydrophobicity for single caseins was pH dependent. In contrast, HI-FPLC was found to be not selective for separation of whey proteins according to their hydrophobicity, but selective for the solubility characteristics related from the used buffer system. Evidence is given that this proposed method can be easily performed, is highly reliable and adaptable to a rapid quantitative differentiation between hydrophobic and hydrophilic areas on protein surfaces