Source: Dissertation Abstracts International, Volume: 40-09, Section: B, page: 4271. / Thesis (Ph.D.)--The Florida State University, 1979.

Source: Dissertation Abstracts International, Volume: 41-01, Section: B, page: 0166. / Thesis (Ph.D.)--The Florida State University, 1979.

Source: Dissertation Abstracts International, Volume: 41-01, Section: B, page: 0167. / Thesis (Ph.D.)--The Florida State University, 1980.

Source: Dissertation Abstracts International, Volume: 41-09, Section: B, page: 3427. / Thesis (Ph.D.)--The Florida State University, 1980.

The regulation at the DNA/RNA level of the biosynthetic pathway of the antibiotic and mycotoxin, patulin, has yet to be elucidated. To lay the groundwork for further research into this area, a library of a genomic DNA sequences for Penicillium patulum was produced in the lambda phage, EMBL-3. Ninety induction-phase-specific clones were selected with a plus/minus screening technique which utilized labeled cDNA produced from mRNA isolated when the culture was uninduced and induced with respect to the patulin pathway. Five of these clones were partially characterized through restriction digest analysis, as well as, Northern dot blot analysis, which showed that some of the sequences are expressed shortly after induction of the pathway and some a few hours later. Eight subclones from the parent clones were produced in the plasmid, pUC18, and partially characterized, leading to a partial restriction map for two of the parent clones, which contain overlapping regions. / Source: Dissertation Abstracts International, Volume: 50-08, Section: B, page: 3452. / Major Professor: Robley J. Light. / Thesis (Ph.D.)--The Florida State University, 1989.

The conformations and dynamics of four tryptophan side-chains in the membrane polypeptide gramicidin A have been investigated by solid state nuclear magnetic resonance. It has been found, through the analyses of the $\sp{15}$N NMR data of fast frozen unoriented and oriented samples in lipid bilayers at various temperatures, that side-chain motions of tryptophans are dominated by the librational motion about the C$\sb\beta$-C$\sb\gamma$ bond. The librational amplitudes have been determined for four tryptophans, and the time scale of such librational motion has been obtained. Motionally averaged side-chain conformations have been achieved from orientational constraints using $\sp2$H and $\sp{15}$N NMR spectra of oriented samples of d$\sb5$-TrpxgA and $\sp{15}$N$\sb{\varepsilon1}$-Trp$\rm\sb x$gA (x = 9, 11, 13, 15). Based on the dynamic and conformational characterization, the interaction between tryptophans and lipid, the effects of tryptophans on gramicidin A secondary structure, and the relationship between the indole dipole moments and the channel conductance have been discussed. Through this study, it is demonstrated that a high resolution characterization of dynamics and structure for important sites in membrane bound proteins and polypeptides can be uniquely achieved by solid state NMR. Such characterizations require method development to separate the entwined effects of structure and dynamics on the nuclear spin interactions. The combined synergetic effect of structure and dynamics yields detailed functional understanding. / Source: Dissertation Abstracts International, Volume: 56-01, Section: B, page: 0218. / Major Professor: Timothy A. Cross. / Thesis (Ph.D.)--The Florida State University, 1994.

Collagen is a major component of connective tissue and accounts for a third of total body protein. Collagen catabolism occurs under both normal and pathological conditions; thus, an understanding of the mechanism of degradation of collagen is essential to all processes that involve connective tissue remodeling and repair. Collagenases are enzymes that are capable of hydrolyzing collagen. Bacterial and tissue collagenases differ in their mode of hydrolysis of the collagen molecule. The work in this thesis describes the kinetics of hydrolysis of the interstitial collagens by both bacterial and human collagenases. / In order to facilitate kinetic studies, an accurate, sensitive and quantitative assay for collagenases has been developed that is based on the hydrolysis of radiolabeled collagens. This assay has been used to generate double-reciprocal plots for the hydrolysis of types I, II and III collagens by the bacterial collagenases derived from Clostridium histolyticum and the tissue collagenases isolated and purified from human neutrophils and human fibroblasts. These studies indicate that human neutrophil collagenase (HNC) preferentially hydrolyzes type I collagen over types II and III collagens. In contrast, human fibroblast collagenase (HFC) prefers type III collagen over types I and II. The Clostridial collagenases do not discriminate between the various types of collagens. A comparison of the k$\sb{\rm cat}$/K$\sb{\rm M}$ values toward hydrolysis of rat type I collagen shows that HNC is more potent than either HFC or the Clostridial collagenases. / The inhibition of HNC by six gold(I) compounds used in the treatment of rheumatoid arthritis has also been investigated. The mechanism by which gold(I) compounds provide remission in rheumatoid arthritis, however, is not understood. Since type II collagen is a major component of joint cartilage and since HNC can hydrolyze type II collagen, the possibility that gold(I) compounds are inhibitions of HNC was investigated. All six gold(I) compounds studied inhibited the p-chloromercuribenzoate-activated latent HNC with varying potencies. Kinetic studies shows that the inhibition is non-competitive and is reversed by zinc. Based on these studies, a model showing the metal binding sites in latent HNC is proposed. / Source: Dissertation Abstracts International, Volume: 49-08, Section: B, page: 3166. / Major Professor: Harold E. Van Wart. / Thesis (Ph.D.)--The Florida State University, 1988.

Single-stranded (ss) DNA is important in regulating biological processes such as transcription due to its ability to form secondary structures. Four ss oligodeoxynucleotides (5'd$\lbrack$GTTAACCATAG$\rbrack$3', 5'd$\lbrack$GTAACCCATAG$\rbrack$3', 5'd$\lbrack$CTCGACGG$\rbrack$3', and 5'd$\lbrack$AACCCATT$\rbrack$3'), which bind to the anticancer drug actinomycin D, and assume folded conformations. The high resolution structure of 5'd$\lbrack$GTTAACCATAG$\rbrack$3' was determined by 2D $\sp1$H NMR and molecular modeling. The oligomer adopts an unusually stable hairpin structure. Its four-nucleotide hairpin loop possesses hydrophobic and hydrophilic faces. The hairpin stem consists of two Watson-Crick A:T base pairs, a G:T mismatch pair, and an unpaired 5'-terminal G. The conformational features of the loop as well as the GT mismatch and the 5'-terminal G of the stem are important in forming the stable hairpin and in actinomycin D recognition. / The first three oligonucleotides bind to actinomycin D with K$\rm \sb{a}$ = 10$\sp6\sim10\sp7$ M$\sp{-1}$. Actinomycin chromophore intercalates into double-stranded sites of secondary structures formed by the oligonucleotides. A guanine residue (G) is required for strong binding of actinomycin D to a single-stranded DNA. GT mismatches play an important role in enhancing binding terminator which induces dissociation of the RNA polymerase from the template. / Source: Dissertation Abstracts International, Volume: 56-11, Section: B, page: 6098. / Major Professor: Randolph L. Rill. / Thesis (Ph.D.)--The Florida State University, 1995.

Source: Dissertation Abstracts International, Volume: 40-06, Section: B, page: 2659. / Thesis (Ph.D.)--The Florida State University, 1979.

Source: Dissertation Abstracts International, Volume: 32-11, Section: B, page: 6197. / Thesis (Ph.D.)--The Florida State University, 1971.