List<String> strPageLayoutsToPersist = 

        new List<string> { "Home Page", 

                           "General Detail Page", 

                           "Email Me Page", 

                           "Category Page" 

                         };

using (SPWeb spWeb = spSite.RootWeb)

{

        PublishingWeb pubWeb = PublishingWeb.GetPublishingWeb(spWeb);

        // Get avaialble page layouts for our content types

        PageLayout[] myPageLayouts = pubWeb.GetAvailablePageLayouts().Cast<PageLayout>()

            .Where(p => strPageLayoutsToPersist.Contains(p.AssociatedContentType.Name))

            .ToArray();

        // Set the available page layouts to our content type

        pubWeb.SetAvailablePageLayouts(myPageLayouts, false);

        // Update the web

        pubWeb.Update();

}