The bacterial flavoprotein monooxygenase carries out an oxygen insertion reaction on cyclohexanone, with ring expansion to form the seven-membered cyclic product epsilon-caprolactone, a transformation quite distinct from the phenol leads to catechol transformation carried out by the bacterial flavoprotein aromatic hydroxylases. Cyclohexanone oxygenase catalysis involves the four-electron of O2 at the expense of a two-electron oxidation of NADPH, concomitant with a two-electron oxidation of cyclohexanone to epsilon-caprolactone. NADPH oxidase activity is fully coupled with oxygen transfer to substrate. Steady-state kinetic assays demonstrate a ter-ter mechanism for this enzyme. Pre-steady-state kinetic assays demonstrate the participation of a 4a-hydroperoxyflavin intermediate during catalysis. In addition to its ketolactonizing activity, cyclohexanone oxygenase carries out S-oxygenation of thiane to thiane 1-oxide, a reaction which represents a nucleophilic displacement by the sulfur upon the terminal oxygen of the hydroperoxide. This is in contrast to cyclohexanone oxygenations where the flavin hydroperoxide acts as a nucleophile. In addition, a stable apoenzyme form is accessible and can be reconstituted with various FAD analogues with up to 100% recovery of enzyme activity. The accumulated results presented here support a Baeyer-Villiger rearrangement mechanism for the enzymatic oxygenation of cyclohexanone.

These data indicated that, in this population, the presence of P. gingivalis in plaque after treatment might be indicative of progressive alveolar bone loss.

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Studies were performed to evaluate the detection of disease-associated bacterial colonization in adult periodontitis patients by the antibody-based Evalusite TestTM (Eastman Kodak Company). The association of test results with disease was assessed by collecting 104 duplicate subgingival plaque samples from 26 patients. Samples were tested for Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Prevotella intermedia using both microbiological culture and the immunoassay test. The sensitivity and specificity of the 2 methods was calculated using %s of positive results in deep periodontal pockets and negative results in shallow subgingival sites. A cutoff >10(4) cultivable counts yielded the greatest discrimination between health and disease on a cross-sectional basis and established this threshold as clinically relevant for the detection of disease-associated levels of bacterial colonization by these three microorganisms. The clinical detection limit of the immunoassay test was observed to coincide with this threshold of >10(4) cultivable counts. Microbiological testing of the 4 deepest pockets using the immunoassay test was determined to be sufficient to yield a 90% confidence of detecting positive patients in a study with 59 adult subjects. The immunoassay test method was also demonstrated to be effective at detecting bacterial colonization in sets of paper point samples that were pooled for analysis. An overall agreement of 94% (288 of 306) was observed when comparing test results for duplicate sets of pooled and individual samples collected from 51 patients. These studies demonstrate that the Evalusite Test is an effective method for detecting clinically relevant colonization by the test bacteria in patients at risk for periodontal disease.