Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 62-74).

published_or_final_version / abstract / toc / Biochemistry / Master / Master of Philosophy

Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 3 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 6 uppsatser.

Vitamin D-binding protein (DBP) is an abundant serum protein, secreted by the liver, which transports vitamin D sterols and is part of an actin scavenging system. In this study, DBP was isolated from horse plasma in a highly reproducible, four step procedure: Affi-gel Blue affinity chromatography, gel filtration, hydroxy1apatite chromatography and anion exchange HPLC. 6-7 mg of DBP were obtained from 80 ml of plasma with a yield of 21-25%. The secondary structure of DBP was calculated from circular dichroism measurements to be 39% α-helix, 42% β-sheet and 19% random coil. A molecular mass of 53,000 ± 3,000 daltons was calculated from electrophoretic gels. Circular dichroism and fluorescence studies revealed that the disulphide bonds of DBP contribute substantial structural stabilization to the molecule with respect to thermal denaturation. Finally, acrylodan-labeled DBP was prepared. The fluorescence of this adduct was sensitive to the binding of actin and to the presence of dithiothreitol. / Science, Faculty of / Chemistry, Department of / Graduate

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisor: Kristi L. Kiick, Dept. of Materials Science & Engineering. Includes bibliographical references.

published_or_final_version / Physiology / Master / Master of Philosophy

published_or_final_version / Biological Sciences / Doctoral / Doctor of Philosophy

Spermatozoa experience a series of physiological alternation upon traveling from the testis to the epididymis in order to acquire motility and capacity necessary to recognize and to fuse with an oocyte. Further maturation and modification of the spermatozoa occur along the journey in the female reproductive tract in a process known as capacitation. p53 protein is a well-known transcription factor involved in guarding of genome integrity by triggering cell cycle arrest and cell death upon DNA damage. p53-binding protein 1 (53BP-1) binds to p53 and enhances p53-mediated transcriptional activity. It has been reported that human spermatozoa produce 53BP-1 for DNA repair in response to oxidative stress. 53BP-1 is expressed in pre-implantation embryos. The current study aimed to identify the expression and subcellular location of 53BP-1 proteins in mouse spermatozoa by immunofluorescence staining. Increased expression of 53BP-1 proteins was found in the swim-up and capacitated mouse spermatozoa. The immunoreactivity was localized to the sperm head and midpiece, suggesting possible roles of 53BP-1 in sperm function. It was also found that mouse oocytes and 1-cell embryo also expressed 53BP-1. The potential function of 53BP-1 in early embryo development was also investigated using 53BP-1 antibody neutralized sperm in in-vitro fertilization. There was no significant difference between the development rate of embryos fertilized with spermatozoa transduced with anti-53BP-1 antibody and those that transduced with the control goat IgG. Further studies are needed to investigate the role of sperm 53BP-1 at later stage of embryo development and implantation. / published_or_final_version / Obstetrics and Gynaecology / Master / Master of Medical Sciences

published_or_final_version / abstract / toc / Chemistry / Master / Master of Philosophy