2003 Beckman Award Winners

Mesha Eaton

Mesha Eaton

Genes Involved in Sperm Function: Investigation of Dual Expression of Hyal5 in The Testis and Epididymis

Mesha Eaton, Hong Zhang, and Patricia A. Martin-DeLeon
Department of Biological Sciences

SPAM1, the Sperm Adhesion Molecule 1, is a highly conserved sperm membrane protein with multiple essential roles in mammalian fertilization. This protein belongs to a group of closely linked hyaluronidases residing on mouse chromosome 6A2, and is responsible for the dissolution of the cumulus cells of the oocyte during fertilization. This is necessary for penetration of the sperm. More recently a Spam1 knockout study revealed that fertility was unaffected and suggested that there was a mouse-specific hyaluronidase, Hyal5, with similar functions to Spam1 (Baba et. al., 2002). The goal of this study was to determine if Hyal5 is redundant to Spam1 in regards to its mRNA and protein expression in the epididymis. An mRNA expression analysis was performed using RT-PCR on both the testis and all three regions of the epididymis (caput, corpus, and cauda), which was rendered sperm-free after excessive washing. RT positive and RT negative reactions were performed and the results, although preliminary, suggest the presence of Hyal5 in the cauda. An attempt was made to study the protein expression in the testis with immunohistochemistry, however due to non-specificity of the antibody the results were inconclusive. A new antibody is being generated to continue these studies.

Chris amEnde

Chris amEnde

De Novo Design of Lanthanide Fingers

Chris am Ende, Mao Ye, Neal Zondlo, and Douglas Taber
Department of Chemistry and Biochemistry

A series of peptides has been synthesized using the 25 amino acid zinc finger motif as a model. The sequence has been altered to allow for lanthanide, instead of zinc, binding. The binding has been analyzed using a several methods. Circular dichroism (CD) was used to monitor the extent of protein folding. The CD data showed characteristic meta bound zinc finger CD spectra upon titration with various lanthanides. Metal binding was also analyzed using fluorescence of tryptophan. In addition, fluorophores have been conjugated to selected amino acids to monitor peptide folding using fluorescence resonance energy transfer (FRET). FRET data gave further evidence of the conformational changes associated with metal binding.