Abstract: The regulatory peptides for constitutive nitric oxide synthase enzymes, and a peptide specific to inducible nitric oxide synthase, as well as derivatives of the peptides, homologous peptides, nucleic acids encoding the peptides, derivatives, and homologous peptides, and antibodies to the peptides, derivatives, and homologous peptides, are disclosed. The peptides, derivatives, homologous peptides, antibodies, and nucleic acids, as well as peptidomimetics, can be used in methods of modulating the activity of nitric oxide synthase enzymes, and also in methods of treating diseases or conditions modulated by production of nitric oxide by nitric oxide synthases. Assays for identifying agents which modulate the activity of the nitric oxide synthase enzymes are also described.

Abstract: Methods for generating chimeric polynucleotides by directed evolution are described. In the methods, splice points of interest are identified within the polynucleotides of a basis set of polynucleotides, preferably through the use of an algorithm that defines the number of splice points and selects the splice points, either by random selection or using information regarding alignment of the polynucleotides. The algorithms can include additional factors, including a definition of a desired distance between splice points, and/or weighing factors to bias selection of splice points. Chimeric polynucleotides are generated using primers (e.g., double primers or non-overlapping primers) and polymerase chain reaction or combinatorial strategies.

Abstract: The regulatory peptides for constitutive nitric oxide synthase enzymes, and a peptide specific to inducible nitric oxide synthase, as well as derivatives of the peptides, homologous peptides, nucleic acids encoding the peptides, derivatives, and homologous peptides, and antibodies to the peptides, derivatives, and homologous peptides, are disclosed. The peptides, derivatives, homologous peptides, antibodies, and nucleic acids, as well as peptidomimetics, can be used in methods of modulating the activity of nitric oxide synthase enzymes, and also in methods of treating diseases or conditions modulated by production of nitric oxide by nitric oxide synthases. Assays for identifying agents which modulate the activity of the nitric oxide synthase enzymes are also described.