Proteins, detection

A selective protein assay was demonstrated, which interfaces the FRET-based ratiometric techniques with the light-harvesting properties of conjugated polymer P4 [85]. Polymer P4 and a negatively charged biotinylated FI probe (Fl-B) were used to optically detect the target protein, Streptavidin. As shown 

---

Glyoxylic acid solution (protein detection) cover 10 g of magnesium powder with water and slowly add 250 mL of a saturated oxalic solution, keeping the mixture cool filter off the magnesium oxalate, acidify the filtrate with acetic acid and make up to a liter with water. 

Fig. 5. Anion-exchange separation of insulin and insulin A- and B-chains, over diethylaminoethyl (DEAF) in a 10.9 x 200 mm column having a volume of 18.7 mL. Sample volume is 0.5 mL and protein concentration ia 16.7 mAf Tris buffer at pH 7.3 is 1 mg/mL for each component ia the presence of EDTA. Eluent (also 16.7 mAf Tris buffer, pH 7.3) flow rate is 1.27 ml,/min, and protein detection is by uv absorbance at 280 nm. The straight line depicts the salt...

While the fluid mosaic model of membrane stmcture has stood up well to detailed scrutiny, additional features of membrane structure and function are constantly emerging. Two structures of particular current interest, located in surface membranes, are tipid rafts and caveolae. The former are dynamic areas of the exo-plasmic leaflet of the lipid bilayer enriched in cholesterol and sphingolipids they are involved in signal transduction and possibly other processes. Caveolae may derive from lipid rafts. Many if not all of them contain the protein caveolin-1, which may be involved in their formation from rafts. Caveolae are observable by electron microscopy as flask-shaped indentations of the cell membrane. Proteins detected in caveolae include various components of the signal-transduction system (eg, the insutin receptor and some G proteins), the folate receptor, and endothetial nitric oxide synthase (eNOS). Caveolae and lipid rafts are active areas of research, and ideas concerning them and their possible roles in various diseases are rapidly evolving. 

FIGURE 10.3 Fraction p/ 6.05-6.20 gradient range from 30.0% to 78.0%. The relative intensities of the band are quantitatively proportional to the amount of corresponding protein detected by UV absorption. 

Proteins detected in CAla and CAld lines, but not observed in MCF10A cells. 

From the results obtained, it was found that compound 10a showed very high fluorescence intensity in the presence of the BSA and BSA/SDS mixture ( F 0.27) together with a noticeable emission enhancement. The presence of dimethyl indo-lenyl increased the affinity of the dyes to both native and denatured proteins. The authors proposed compound 10a for further studies as fluorescent probes for protein detection. 

Suzuki Y, Yokoyama K (2007) A protein-responsive chromophore based on squaraine and its application to visual protein detection on a gel for SDS-PAGE. Angew Chem Int Ed 46 4097 1099... 

Wattiez R et al. Human bronchoalveolar lavage fluid protein two-dimensional database study of interstitial lung diseases. Electrophoresis 2000 21 2703-2712. Yanagida M et al. Matrix assisted laser desorption/ionization-time of flight-mass spectrometry analysis of proteins detected by anti-phosphotyrosine antibody on two-dimensional-gels of fibrolast cell lysates after tumor necrosis factor-alpha stimulation. Electrophoresis 2000 21 1890-1898. 

Karpova, T. S., Baumann, C. T., He, L., Wu, X., Grammer, A., Lipsky, P., Hager, G. L. and McNally, J. G. (2003). Fluorescence resonance energy transfer from cyan to yellow fluorescent protein detected by acceptor photobleaching using confocal microscopy and a single laser. J. Microsc. 209, 56-70. 

Kozlov, I.A., Melnyk, P.C., Stromsborg, K.E., Chee, M.S., Barker, D.L., and Zhao, C. (2004) Efficient strategies for the conjugation of oligonucleoitdes to antibodies enabling highly sensitive protein detection. Biopolymers 73(5), 621-630. 

P. Bergveld, A critical evaluation of direct electrical protein detection methods. Biosens. Bioelectron. 6, 55-72 (1991). 

S. Koch, P. Woias, L.K. Meixner, S. Drost, and H. Wolf, Protein detection with a novel ISFET-based zeta potential analyzer. Biosens. Bioelectron. 14, 413—421 (1999). 

Fig. 8.11 (A and B) Expression and purification of insulin-polymer fusion protein detected in copper (A) and Coomassie (B) stained gels. The same gel was first stained with copper, destained and restained with Coomassie R-250. Lane 1 Prestained marker Lane 2 Purified extract of polymer-insulin fusion protein from the chloroplast vector pSBL-OC-40Pris Lane 3 Reverse orientation of fusion protein from pSBL-OC-40Pris Lane 4 Purified extract of polymer-insulin fusion protein from the chloroplast vector pLD-OC-40Pris ...

Silver also binds to proteins, an observation that forms the basis of an extremely sensitive method of protein detection. This technique is used extensively to detect proteins in electrophoretic gels, as discussed in the next section. 

Vollmer, F. Braun, D. Libchaber, A. Khoshsima, M. Teraoka, I. Arnold, S., Protein detection by optical shift of a resonant microcavity, Appl. Phys. Lett. 2002, 80, 4057 4059... 

Lee, M. R. Fauchet, P. M., Two dimensional silicon photonic crystal based biosensing platform for protein detection, Opt. Express 2007, 15, 4530 4535... 

---