RadioSource.NET: Case-study of a Collaborative Land-Grant Internet Audio Project

RadioSource.NET (http://radiosource.net) is a Web-portal news site for land-grant university radio programming. The project is a collaborative venture among university communication departments with the following goals: to share resources; increase online distribution; and promote access to agricultural and natural and life science research. This article is a case study of RadioSource.NET. The evolution of the RadioSource.NET project is examined with emphasis on the process of establishing and maintaining online collaborative partnerships within academia. The project’s development is described and discussed, and Wheeler, Valacich, Alavi, and Vogel’s (1995) framework for technology-mediated interinstitutional relationships for collaborative learning is used to help organize information and evaluate the project’s effectiveness. RadioSource.NET project is an example of successful university collaboration in new media. By utilizing a flexible system design, RadioSource.NET capitalizes on collaborative strengths such as increased innovation and efficiency, and it is anticipated that the project model can serve as a useful resource for other online collaborative endeavors utilizing emerging technologies

A Critical Tryptophan and Ca2+ in Activation and Catalysis of TPPI, the Enzyme Deficient in Classic Late-Infantile Neuronal Ceroid Lipofuscinosis

Tripeptidyl aminopeptidase I (TPPI) is a crucial lysosomal enzyme that is deficient in the fatal neurodegenerative disorder called classic late-infantile neuronal ceroid lipofuscinosis (LINCL). It is involved in the catabolism of proteins in the lysosomes. Recent X-ray crystallographic studies have provided insights into the structural/functional aspects of TPPI catalysis, and indicated presence of an octahedrally coordinated Ca(2+).Purified precursor and mature TPPI were used to study inhibition by NBS and EDTA using biochemical and immunological approaches. Site-directed mutagenesis with confocal imaging technique identified a critical W residue in TPPI activity, and the processing of precursor into mature enzyme.NBS is a potent inhibitor of the purified TPPI. In mammalian TPPI, W542 is critical for tripeptidyl peptidase activity as well as autocatalysis. Transfection studies have indicated that mutants of the TPPI that harbor residues other than W at position 542 have delayed processing, and are retained in the ER rather than transported to lysosomes. EDTA inhibits the autocatalytic processing of the precursor TPPI.We propose that W542 and Ca(2+) are critical for maintaining the proper tertiary structure of the precursor proprotein as well as the mature TPPI. Additionally, Ca(2+) is necessary for the autocatalytic processing of the precursor protein into the mature TPPI. We have identified NBS as a potent TPPI inhibitor, which led in delineating a critical role for W542 residue. Studies with such compounds will prove valuable in identifying the critical residues in the TPPI catalysis and its structure-function analysis