Abstract: Methods for enhancing a biological activity, for example, catalytic activity, of a lipase, are provided. In some embodiments, the methods include the step of alkylating one or more cysteine residues present within the lipase. Also provided are modified polypeptides for which a biological activity is enhanced by the disclosed methods, methods for using the disclosed polypeptides, including for the transesterification of renewable oils to produce a biofuel, and cell free systems that include a lipase, to which one or more moieties, such as steroidal moieties, are conjugated.

Abstract: Methods for enhancing a biological (e.g., catalytic) activity of a lipase, are provided. In some embodiments, the methods include the step of alkylating one or more cysteine residues present within the lipase. Also provided are modified polypeptides for which a biological activity is enhanced by the disclosed methods, methods for using the disclosed polypeptides, including for the transesterification of renewable oils to produce a biofuel, and cell free systems that include a lipase, to which one or more moieties, such as steroidal moieties, are conjugated.

Abstract: Compositions and methods for enhancing paracellular permeability at an absorption site in a subject are disclosed. The method includes: (a) administering an effective amount of a phospholipase C inhibitor to a subject at a time in which enhanced paracellular permeability is desired; and (b) enhancing paracellular permeability in the subject at the absorption site through the administering of the effective amount of the phospholipase C inhibitor. The disclosed compositions and methods provide enhanced absorption of a hydrophilic drug in a subject.

Abstract: A system for simulating metabolism of a compound in a mammal is disclosed that includes a metabolism simulation model of a mammalian liver. This model has equations which, when executed on a computer, calculate the rate of metabolism of the compound in the cells of the mammalian liver and a rate of transport of the compound into the cells, wherein the simulation model determines an amount of the metabolism product. The rate of metabolism may be a rate of depletion of the compound. The metabolism product may be an amount of the compound remaining after the compound's first passage through the mammalian liver (This is not necessarily limited to first pass, nor would it need to be limited to the liver. Intestinal metabolism could also be modeled). The rate of metabolism may alternatively be a rate of accumulation of a metabolite of the compound.

Abstract: Compositions and methods for enhancing paracellular permeability at an absorption site in a subject are disclosed. The method includes: (a) administering an effective amount of a phospholipase C inhibitor to a subject at a time in which enhanced paracellular permeability is desired; and (b) enhancing paracellular permeability in the subject at the absorption site through the administering of the effective amount of the phospholipase C inhibitor. The disclosed compositions and methods provide enhanced absorption of a hydrophilic drug in a subject.

Abstract: A method of screening a candidate compound for susceptibility to metabolism by a selected enzyme. The method includes the steps of reacting the candidate compound, an indicator compound precursor and the selected enzyme, the enzyme characterized as having a side reaction associated with metabolic activity of the enzyme wherein a chemical species capable of reacting with the indicator compound precursor is produced; and detecting an indicator compound, the indicator compound produced from the indicator compound precursor by reaction with the chemical species produced from the side reaction associated with metabolic activity of the enzyme, the detection of the indicator compound indicating the susceptibility of the candidate compound to metabolism by the enzyme. A preferred example of the selected enzyme is a cytochrome P450 (CYP).

Abstract: A method of screening a candidate compound for susceptibility to metabolism by a selected enzyme. The method includes the steps of reacting the candidate compound, an indicator compound precursor and the selected enzyme, the enzyme characterized as having a side reaction associated with metabolic activity of the enzyme wherein a chemical species capable of reacting with the indicator compound precursor is produced; and detecting an indicator compound, the indicator compound produced from the indicator compound precursor by reaction with the chemical species produced from the side reaction associated with metabolic activity of the enzyme, the detection of the indicator compound indicating the susceptibility of the candidate compound to metabolism by the enzyme. A preferred example of the selected enzyme is a cytochrome P450 (CYP).