Protein separation using membrane-encapsulated soluble ligand conjugates

A new approach for isolating and recovering biological macromolecules using membrane-encapsulated soluble ligand conjugates was investigated. Membrane-encapsulated solid adsorbents have been successfully developed and employed in our laboratory to isolate and purify proteins and enzymes directly from culture broths. This new concept also makes it possible to use soluble ligand conjugates instead of solid adsorbents inside membrane capsules. In this work, model membrane-encapsulated soluble and insoluble ligands comprising Blue Dextran and Blue Sepharose entrapped within calcium alginate membranes were studied to compare adsorption characteristics such as capacities and rates. Experimental results suggest that membrane-encapsulated soluble ligands may be expected to result in higher overall adsorption capacity compared to membrane-encapsulated solid adsorbents with comparable adsorption rates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28604/1/0000413.pd

Clinical Significance of Serum Biomarkers in Pediatric Solid Mediastinal and Abdominal Tumors

Childhood cancer is the leading cause of death by disease among U.S. children between infancy and age 15. Despite successes in treating solid tumors such as Wilms tumor, disappointments in the outcomes of high-risk solid tumors like neuroblastoma have precipitated efforts towards the early and accurate detection of these malignancies. This review summarizes available solid tumor serum biomarkers with a special focus on mediastinal and abdominal cancers in children

Photoaffinity labeling and photoaffinity cross-linking of phosphofructokinase-1 from Saccharomyces cerevisiae by 8-azidoadeninenucleotides

Phosphofructokinase-1 from Saccharomyces cerevisiae is composed of four alpha and four beta-subunits, each of them carrying catalytic and regulatory bindings sites for MgATP. In this paper, various photoaffinity labels, such as 8-azidoadenosine 5'-triphosphate, 8-azido-1,N6-ethenoadenosine 5'-triphosphate, and 8-N3-3'(2')-O-biotinyl-8-azidoadenosine 5'-triphosphate have been used to study their interaction with the enzyme in the dark and during irradiation. All nucleotidetriphosphates function as phosphate donor forming fructose 1,6-bisphosphate from fructose 6-phosphate. However, the kinetic analysis revealed distinctly differences between them. Photolabeling causes a decrease in enzyme activity to a similar extent, and ATP acts as competitive effector to inactivation. Three bifunctional diazidodiadeninedinucleotides (8-diN3AP4A, monoepsilon-8-diN3AP4A, and diepsilon-8-diN3AP4A) were applied for studying the spatial arrangement of the nucleotide binding sites. No cross-linking of the subunits was obtained by irradiation of the enzyme with 8-diN3AP4A. Photolabeling with diepsilon-8-diN3AP4A resulted in the formation of two alpha-beta cross-links with different mobilities in the SDS-polyacrylamide gel electrophoresis, while monoepsilon-8-diN3AP4A yielded only one alpha-beta cross-link. Because an interfacial location of the catalytic sites between two subunits is less likely, we suggest that the formation of cross-linked subunits may be the result of specific interactions of the bifunctional photolabels with regulatory sites at the interface of both subunits