1. Two methods are described for the preparation of 'proalbumin' in good yields from rat liver. 2. One of the methods does not depend on the use of specific antisera. 3. The product from both methods is identical as judged by electrophoresis on polyacrylamide gel, isoelectric focusing on pH gradients, ion-exchange chromatography and quantitative immunoelectrophoresis. The protein also appears t...

A glycoprotein resembling ovomucoid was purified from chorioallantoic membranes of 12.5 day chick embryos by a sequential procedure involving zinc chloride precipitation, hydroxylapatite chromatography, and ion exchange chromatography on DEAEand CM-cellulose. The resulting preparation was homogeneous as indicated by polyacrylamide gel electrophoresis at 3 pH values, isoelectric focusing, ultrac...

Streptolysin-O was isolated from culture supernatants of group-A beta-hemolytic streptococci (Richards strain) by ammonium sulfate and polyethylene glycol precipitation, DEAE-ion exchange chromatography, preparative isoelectric focusing, and chromatography on Sephacryl S-300. Two forms of the toxin possessing similar hemolytic capacity were identified. The native toxin was a single polypeptide ...

Fractionation of the culture supernatant fluids of a cornea-virulent strain of Pseudomonas aeruginosa by ammonium sulfate precipitation, diafiltration, isoelectric focusing, ion-exchange chromatography, gel filtration, and sucrose density gradient centrifugation failed to separate the rabbit cornea-damaging activity and the in vitro protease activity of the preparations. Three proteases having ...

The aim of the present study is to elucidate the enzymological and chemical properties of the plasminogen activator in bile, bilokinase. A bilokinase preparation was obtained from 94.2 liters of bovine gall bladder bile through seven purification steps, two of which employed a precipitation method in which ammonium sulfate and acetone were used sequentially. Twenty mg of bilokinase preparation ...

Mouse placental lactogen was purified 1840-fold from BALB/c placentae from days 14-18 of gestation with an overall yield of 29%. The purification procedure included alkaline homogenization and extraction, ammonium sulfate precipitation, hydrophobic interaction chromatography on Phenyl-Sepharose, ion-exchange chromatography on CM- and DEAE-cellulose, and gel exclusion chromatography on Sephadex ...

Theoretical distribution of isoelectric points (pI values) of human blood proteins exhibits multimodality with a deep minimum in the range between pI 7.30 and 7.50. Considering that the pH of human blood is 7.4±0.1, normal forms of human proteins tend to eschew this specific pI region, thus avoiding charge neutrality that can result in enhanced precipitation. However, abnormal protein isoforms ...