Enzymatic oxidation of unconjugated @entity648 to assess its interactions with XXXX .

@entity10737 @entity1 @entity7362 @entity648 @entity6741 @entity2118 @entity460 @entity141 @entity3645
The rate of peroxidation of unconjugated @entity648 (UCB), catalyzed by horseradish peroxidase (HRP), has been employed by Jacobsen (1969. FEBS Lett. 5: 112-114) to assess the fraction of unbound UCB in the presence of serum albumin. We used this method to examine the interactions of UCB with @entity7362 (TC) at pH 8.2, assuming solubilization of UCB by TC is due to pigment binding and/or to partitioning into the micelle, thus rendering UCB unavailable for peroxidation. Inhibition of UCB peroxidation conformed with predictions based on these assumptions and demonstrated significant interaction of UCB with both monomeric and micellar TC. Although significant inhibition of UCB peroxidation was seen with TC monomer, inhibition was even greater with TC micelles. In contrast, @entity10737 , another substrate of HRP, acted very differently in the presence of TC. Inhibition of @entity10737 peroxidation by TC was much less than with UCB and occurred primarily with monomeric TC, with little further inhibition in the micellar range. The results of this study suggest that at @entity7362 concentrations above 50 mM, similar to the physiologic @entity6741 concentrations in @entity1 bile, at least 99% of UCB is bound to @entity6741 , dramatically decreasing the concentration of unbound UCB. Since @entity3645 also bind @entity141 , they play a dual role in protection against the precipitation of @entity460 bilirubinate from bile. Therefore, @entity3645 are a major factor in the prevention of the formation and growth of @entity2118 .
