Amidation inhibitors 4-phenyl-3-butenoic acid and 5-(acetylamino)-4-oxo-6-phenyl-2-hexenoic acid methyl ester are novel HDAC inhibitors with anti-tumorigenic properties.

4-Phenyl-3-butenoic acid (PBA) is an inhibitor of peptidylglycine alpha-amidating monooxygenase with anti-inflammatory properties that has been shown to inhibit the growth of ras-mutated epithelial and human lung carcinoma cells. In this report, we show that PBA also increases the acetylation levels of selected histone subtypes in a dose and time dependent manner, an effect that is attributable to the inhibition of histone deacetylase (HDAC) enzymes. Comparison studies with the known HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) using high resolution two-dimensional polyacrylamide gels and Western analysis provide evidence that PBA acts as an HDAC inhibitor within cells.

H2B- and H3-specific histone deacetylases are required for DNA methylation in Neurospora crassa.

Neurospora crassa utilizes DNA methylation to inhibit transcription of heterochromatin. DNA methylation is controlled by the histone methyltransferase DIM-5, which trimethylates histone H3 lysine 9, leading to recruitment of the DNA methyltransferase DIM-2. Previous work demonstrated that the histone deacetylase (HDAC) inhibitor trichostatin A caused a reduction in DNA methylation, suggesting involvement of histone deacetylation in DNA methylation.

Extensive and varied modifications in histone H2B of wild-type and histone deacetylase 1 mutant Neurospora crassa.

DNA methylation is deficient in a histone deacetylase 1 (HDA1) mutant (hda-1) strain of Neurospora crassa with inactivated histone deacetylase 1. Difference two-dimensional (2D) gels identified the primary histone deacetylase 1 target as histone H2B. Acetylation was identified by LC-MS/MS at five different lysines in wild-type H2B and at 11 lysines in hda-1 H2B, suggesting Neurospora H2B is a complex combination of different acetylated species.

Development of albumin microspheres containing Sp H1-DNA complexes: a novel gene delivery system.

This study investigated the stability and transfection efficiency of plasmid DNA (pDNA) and sea urchin sperm histone H1 (Sp H1) complexes embedded in albumin microsphere formulations. Sp H1 increased the stability and transfection efficiency of pDNA, while providing a favourable sustained pDNA release profile. Encapsulating Sp H1-complexed pDNA into albumin microspheres further protected the pDNA from physical stress and heparin treatment.

Purification and analysis of variant and modified histones using 2D PAGE.

Two-dimensional (2D) polyacrylamide gel electrophoresis (PAGE) systems employing combinations of acetic acid/urea (AU), acetic acid/urea/Triton X-100 (AUT) and sodium dodecyl sulfate (SDS) gel formulations are uniquely effective for resolution of histone variants and their modified derivatives. Coupled with Western transfer methods using modification-specific antibodies and recent advances in mass spectrometry, 2D PAGE emerges as a versatile tool for histone purification and analysis. This chapter describes 2D PAGE gel systems appropriate for histone proteins, including detailed procedures for designing, running, and staining gels.

Clinical outcomes of penicillin skin testing.

Background: Penicillin or cephalosporin allergy is a common problem with antibiotic drug prescribing in hospitalized patients.

Objectives: To study the various clinical outcomes of penicillin skin testing (PST) in a community teaching hospital and to determine the percentage of patients who have an antibiotic drug modification after PST.

Methods: This study was a retrospective medical record review of all inpatients who underwent PST in 6.

Multiple roles for Saccharomyces cerevisiae histone H2A in telomere position effect, Spt phenotypes and double-strand-break repair.

Telomere position effects on transcription (TPE, or telomeric silencing) are nucleated by association of nonhistone silencing factors with the telomere and propagated in subtelomeric regions through association of silencing factors with the specifically modified histones H3 and H4. However, the function of histone H2A in TPE is unknown. We found that deletion of either the amino or the carboxyltails of H2A substantially reduces TPE.