Conalbumin

FIGURE l.l Hydrophobic interaction and reversed-phase chromatography (HIC-RPC). Two-dimensional separation of proteins and alkylbenzenes in consecutive HIC and RPC modes. Column 100 X 8 mm i.d. HIC mobile phase, gradient decreasing from 1.7 to 0 mol/liter ammonium sulfate in 0.02 mol/liter phosphate buffer solution (pH 7) in 15 min. RPC mobile phase, 0.02 mol/liter phosphate buffer solution (pH 7) acetonitrile (65 35 vol/vol) flow rate, I ml/min UV detection 254 nm. Peaks (I) cytochrome c, (2) ribonuclease A, (3) conalbumin, (4) lysozyme, (5) soybean trypsin inhibitor, (6) benzene, (7) toluene, (8) ethylbenzene, (9) propylbenzene, (10) butylbenzene, and (II) amylbenzene. [Reprinted from J. M. J. Frechet (1996). Pore-size specific modification as an approach to a separation media for single-column, two-dimensional HPLC, Am. Lab. 28, 18, p. 31. Copyright 1996 by International Scientific Communications, Inc.. Shelton, CT.]... 

Fig. 4. HPHIC of standard proteins on the weak hydrophobic columns. The SynChro-pack PROPYL column was 25x0.41 cm Poly (alkyl aspartamid)-silicas were packed into 20 x 0.46 cm columns. Sample 25 pi containing 25 pg of each protein in buffer A. Buffer A 1.8 mol/1 ammonium sulphate + 0.1 mol/1 potassium phosphate, pH 7.0. Buffer B 0.1 mol/1 potassium phosphate, pH 7.0. Gradient 40-min linear 0-100% buffer B. Flow rate 1 ml/min. Detection A220 = 1-28 a.u.f.s. Peaks a = cytochrome C, b = ribonu-clease A, c = myoglobin, d = conalbumin, e = neochymotrypsin, / = a-chymotrypsin, g - a-chymotrypsinogen A [48]...

Figure 18 Very-high-speed gradient anion exchange chromatography of proteins. Column 0.46 x 3.5 cm ZipSep AX, 3 p. Eluent Tris-HCl, pH 8.0, operated on a gradient from 0-0.5 M NaCl. Flow rate 2ml/min. Detection UV absorbance at 280 nm. (1) Ribonuclease A, (2) carbonic anhydrase, (3) conalbumin, (4) bovine serum albumin. (Reproduced from Hatch, R. G., J. Chromatogr. Sci., 31, 469,1993. By permission of Preston Publications, A Division of Preston Industries, Inc.)...

Figure 9 Three-dimensional cationic CITP of (A) blank (B) lysozyme (LYSO), creatinine (CREAT), conalbumin (CAL), y-amino-n-butyric acid (GABA), and ovalbumin (OVA) (C) OVA spiked with CREAT and GABA. Capillary 90 cm (length to the detector, 70 cm) x 75 p i.d. leader 10 mM potassium acetate and acetic acid with 0.3% HPMC, pH 4.75 terminator 10 mM acetic acid sample 10 to 30 mg/ml proteins dissolved in leader without HPMC voltage 20 kV. (From Gebauer, P. and Thormann, W.,. Chromatogr., 558, 423, 1991. With permission.)...

As examples. Table 8 records some observations on d—d and charge transfer absorption bands in metal/protein systems. The examination of the spectrum of cobalt carbonic anhydrase (d—d) and of iron conalbumin (charge-transfer) permitted a prediction of the ligands from the protein to the metal. The predictions have now been substantiated by other methods. 

Iron transport agents may belong to the protein or non-protein class. In the former group are found the animal proteins transferrin (25), lactoferrin (26) and conalbumin (27). The low molecular weight iron carrying compounds from microorganisms, the siderochromes, may occur with or without a bound metal ion. Typically, severe repression of biosynthesis of these substances can be expected to set in at an iron concentration of ca. 2 x 10-5 g atoms/liter (28). Most, but not all, of these substances can be described as phenolates or hydroxamates (4). 

Fig. 5. Effect of the flow rate on the separation efficiency. Separation of a protein mixture at six different flow rates (40,80,120,160,200 and 240 ml/min) normalized to the elution volume. Conditions Column 80 ml CIM DEAE Tube Monolithic Column Mobile phase buffer A 20 mM Tris-HCl buffer, pH 7.4 buffer B 20 mM Tris-HCl buffer + 1 M NaCl, pH 7.4 Gradient 0-100% buffer B in 200 ml Sample 2 mg/ml of myoglobin (peak 1), 6 mg/ml of conalbumin (peak 2) and 8 mg/ml of soybean trypsin inhibitor (peak 3) dissolved in buffer A Injection volume 1 ml Detection UV at 280 nm. (Reprinted with permission from Podgornik A, Barut M, Strancar A, Josic D, Koloini T (2000) Anal Chem 72 5693)...

Figure 4.9 Anion-exchange liquid chromatography of acidic proteins. Column, Asahipak ES502N eluent, 20 min linear gradient of sodium chloride from 0 to 500 pM in 50 mM bis-tris/HCl buffer pH 7.0 flow rate, 1ml min-1 detection, UV 280 nm. Peaks-. 1, conalbumin (Mr 77000-88000, pi 6.0-6.8) 2, ovalbumin (Mt 45000, pi 4.6) 3, trypsin inhibitor (Mr 8000, pi 4.5) and 4, / -lactoglobulin (Mr 18400, pi 5.1).

III. Albumins, eg., ovalbumin, conalbumin, serum albumin, various... 

Transferrin of blood plasma is encoded by a separate gene but has a similar structure. Transferrin of chickens appears to be identical to conalbumin of egg whites. The iron-binding proteins of body fluids are sometimes given the group name siderophilins. Transferrins may function not only in transport of iron throughout the body but also as iron buffers that provide a relatively constant iron concentration within tissues. 

Ovalbumin Conalbumin Ovomucoid Lysozyme Vitellogenin apo-VLDL Glucose-6-P-dehydrogenase Oviduct Oviduct (liver) Oviduct Oviduct Liver Liver Uterus Thyroid Hormones Carbamyl phosphate synthase Growth hormone Prolactin ( ) a-Glycerophosphate dehydrogenase Malic enzyme Liver Pituitary Pituitary Liver (mitochondria) Liver... 

In the liver, the product of the conalbumin gene is called transferrin. 

Very little is known about the transport of nickel, manganese and cobalt. Plasma transferrin, conalbumin and citrate have been suggested to serve as carrier ligands. Transferrin is the main transport protein for vanadium in humans, and will transfer vanadium to ferritin. 

Ovotransferrin is also obtained from the white portion of a chicken egg and has been used as a chiral selector in liquid chromatography. This protein is also called conalbumin. It is a metal ion (iron, copper, manganese, and zinc) binding protein of molecular mass 70,000-78,000 and with an isoelectric point of 6.1-6.6. This protein is sensitive to acids and heat. 

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