Bovine viral diarrhea virus: affinity chromatography on Crotalaria juncea lectin.

Attempts were made to purify bovine viral diarrhea virus by chromatography on Crotalaria juncea lectin coupled to Sepharose 2B. A recovery of abut 65% of viral infectivity after desorption was obtained. Electron microscopy revealed mostly de-enveloped particles, rather uniform in appearance but differing in size. Immunodiffusion tests with immune calf sera showed precipitation lines of identity between the desorbed virus and extracts from infected cell cultures.

Salt-promoted adsorption of proteins onto amphiphilic agarose-based adsorbents. II. Effects of salt and salt concentration.

The effects of different types of salts and salt concentrations on the selectivity in the adsorption of serum proteins have been compared for the amphiphilic agarose-based adsorbents Phenyl-Sepharose, Octyl-Sepharose, butyl-agarose and mercaptopyridine-derivatized agarose. By use of multivariate analysis, the complex interrelationships for the different combined effects were evaluated. From these analyses conclusions about similarities and/or dissimilarities in the mechanisms involved in adsorption of proteins on respective adsorbent were made.

Important parameters in semi-dry electrophoretic transfer.

The efficiency of semi-dry electrophoretic transfer after sodium dodecyl sulfate (SDS)-electrophoresis using PhastGel media was investigated in a model system using three isotope labelled proteins. To give a full picture of the blotting process the amount of protein present in the gel, membranes, and filter papers was determined after different transfer times. The influence of the transfer buffer, commonly used additives such as methanol and SDS, and several different immobilizing matrices was investigated. Soybean trypsin inhibitor, bovine serum albumin, and ferritin were used as model proteins to study the effect of size on transfer efficiency. Basically, all three stages of the blotting process decide the result; the elution of protein from the gel, the immobilization of protein to the membrane, and the loss of material from the membrane during transfer. A theoretical explanation for the observed poor binding to a second membrane is discussed. Our results show that the buffer composition has little influence on the efficiency of transfer from the gel, but can be significant to the binding capacity of the membrane. In all experiments performed, there was never one moment during the transfer when all protein was eluted from the gel and simultaneously still bound to the membrane. The highest recovery in the membrane was obtained at different time intervals for different proteins. This indicates that quantitative transfer procedures cannot be generalized. However, obtaining an optimal method for reliable quantification of a specific protein or group of proteins is possible. For general protein staining of nitrocellulose and polyvinylidene difluoride membranes, a highly sensitive silver staining method requiring only 15 min has been used.

Bovine viral diarrhea virus: purification of surface proteins in detergent-containing buffers by fast protein liquid chromatography.

Bovine viral diarrhea virus was purified by lectin chromatography. The glycoprotein peplomers were dissociated from the virion by treatment with detergent. By a second lectin gel chromatography the glycoconjugates containing terminal galactose were prepared. In combination with lectin affinity chromatography, ion-exchange chromatography on Mono-Q in the presence of the low-UV-absorbing detergent Berol 172 proved to be a powerful technique both for analytical and preparative applications.