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Molecular preservation in non-avian dinosaurs is controversial. We present multiple lines of evidence that endogenous proteinaceous material is preserved in bone fragments and soft tissues from an 80-million-year-old Campanian hadrosaur, Brachylophosaurus canadensis [Museum of the Rockies (MOR) 2598]. Microstructural and immunological data are consistent with preservation of multiple bone matrix and vessel proteins, and phylogenetic analyses of Brochylophosourus collagen sequenced by mass spectrometry robustly support the bird-dinosaur clade, consistent with an endogenous source for these collagen peptides. These data complement earlier results from Tyrannosaurus rex (MOR 1125) and confirm that molecular preservation in Cretaceous dinosaurs is not a unique event.

Results show that the intermediates of catestatin are formed from proteolytic cleavage of bovine chromogranin A at the C-terminus of paired basic andmonobasic residues. The active catestatin production occurs by N-terminus dibasic and monobasic residues of chromogranin A. Data indicate that chromogranin A cleavage at specific residues are essential steps for catestatin peptide regulation of nicotinic cholinergic-induced catecholamine release.

Peptide metabolism is a complex process that involves many proteins working in concert. Mass spectrometry–based global peptide profiling of mice lacking dipeptidyl peptidase 4 (DPP4) identified endogenous DPP4 substrates and revealed an unrecognized pathway during proline peptide catabolism that interlinks aminopeptidase and DPP4 activities. Together, these studies elucidate specific aspects of DPP4-regulated metabolism and, more generally, highlight the utility of global peptide profiling for studying peptide metabolism in vivo. [ABSTRACT FROM AUTHOR]

The MYST family of histone acetyltransferases (HATs) plays critical roles in diverse cellular processes, such as the epigenetic regulation of gene expression. Lysine autoacetylation of the MYST HATs has recently received considerable attention. Nonetheless, the mechanism and function of the autoacetylation process are not well defined. To better understand the biochemical mechanism of MYST autoacetylation and the impact of autoacetylation on the cognate histone acetylation, we carried out detailed analyses of males-absent-on-the-first (MOF), a key member of the MYST family. A number of mutant MOF proteins were produced with point mutations at several key residues near the active site of the enzyme. Autoradiography and immunoblotting data showed that mutation of these residues affects the autoacetylation activity and HAT activity of MOF by various degrees demonstrating that MOF activity is highly sensitive to the chemical changes in those residues. We produced MOF protein in the deacetylated form by using a nonspecific lysine deacetylase. Interestingly, both the autoacetylation activity and the histone acetylation activity of the deacetylated MOF were found to be very close to that of wild-type MOF, suggesting that autoacetylation of MOF only marginally modulates the enzymatic activity. Also, we found that the autoacetylation rates of MOF and deacetylated MOF were much slower than the cognate substrate acetylation. Thus, autoacetylation does not seem to contribute to the intrinsic enzymatic activity in a significant manner. These data provide new insights into the mechanism and function of MYST HAT autoacetylation. [ABSTRACT FROM AUTHOR]

The Association of Biomolecular Resource Facilities 2003 Edman Sequencing Research Group (ABRF-ESRG'03) sample is the 15th in a series of studies designed to allow participating members to evaluate their abilities to analyze the N-terminus of a protein or peptide using automated Edman degradation chemistry. It is a follow-up study to the ESRG'02 sample, which was a single protein with a heterogeneous N-terminus. Both the 2002 and 2003 samples were obtained from the same protein complex and were resolved by SDS-PAGE followed by electrophoretic transfer to PVDF membrane. The ABRF-ESRG'03 sample had an apparent molecular weight of 49 kDa and a single N-terminus, with initial yields of approximately 2 pmol. Participants were asked to sequence 25 residues and return their results to the ESRG for analysis along with two completed surveys and an area/pmol table for repetitive and initial yield calculations. Data for 46 responses are presented which include initial yields, repetitive yields, sequencer performance, and ability to identify the protein.

The ABRF-2002 Edman Sequencing Research Group (ESRG) sample (ABRF-2002ESRG) was the 14th in a yearly series designed as an education and self-evaluation tool for laboratories performing Edman sequence analysis. This year's study used a known protein with a heterogeneous amino-terminus, and thus was one of the more challenging protein samples distributed by an Association for Biomolecular Resource Facilities (ABRF) research group. The sample was originally submitted to an ESRG member's lab, and after analysis was thought to demonstrate an analytical problem that would be of interest to the general sequencing community. The protein was purified using commercially available, pre-cast sodium dodecyl sulfate-polyacrylamide gels and transferred to polyvinylidene fluoride.Protein bands were distributed to 72 members of the ABRF who requested ABRF-2002ESRG, along with a data instruction sheet and a brief survey. Participating members were requested to report observed raw data, interpret the data as they normally would for an investigator, and identify the protein using a database search. Study results from 31 responses are presented to show how labs fared with a difficult but sequenceable sample.