Donald L. Coppock

Sulfhydryl oxidases: emerging catalysts of protein disulfide bond formation in eukaryotes.

Members of the Quiescin-sulfhydryl oxidase (QSOX) family utilize a thioredoxin domain and a small FAD-binding domain homologous to the yeast ERV1p protein to oxidize sulfhydryl groups to disulfides with the reduction of oxygen to hydrogen peroxide. QSOX enzymes are found in all multicellular organisms for which complete genomes exist and in Trypanosoma brucei, but are not found in yeast. The avian QSOX is the best understood enzymatically: its preferred substrates are peptides and proteins, not monothiols such as glutathione. Mixtures of avian QSOX and protein disulfide isomerase catalyze the rapid insertion of the correct disulfide pairings in reduced RNase. Immunohistochemical studies of human tissues show a marked and highly localized concentration of QSOX in cell types associated with heavy secretory loads. Consistent with this role in the formation of disulfide bonds, QSOX is typically found in the cell in the endoplasmic reticulum and Golgi and outside the cell. In sum, this review suggests that QSOX enzymes play a significant role in oxidative folding of a large variety of proteins in a wide range of multicellular organisms.

The National Niemann–Pick C1 disease database: Report of clinical features and health problems

Niemann–Pick type C1 (NPC1) disease is an autosomal recessive disorder characterized clinically by neonatal jaundice, hepatosplenomegaly, vertical gaze palsy, ataxia, dystonia, and progressive neurodegeneration. The present study provides basic clinical and health information from the National Niemann–Pick C1 disease database that was obtained using a clinical questionnaire of 83 questions mailed to families affected by NPC1 disease living in the United States. The study was conducted over a 1‐year period, during which time parents/caregivers and physicians completed the clinical questionnaire. Sixty‐four percent (87/136) of the questionnaires were returned, with 53% and 47% representing male and female NPC1 patients, respectively. The average age of diagnosis for NPC1 disease was 10.4 years, with one‐half of patients being diagnosed before the age of 6.9 years. The average age of death for NPC1 disease was 16.2 years, with one‐half of patients dying before the age of 12.5 years. A common clinical symptom reported at birth was neonatal jaundice (52%), followed by enlargement of the spleen (36%) and liver (31%); ascites (19%) and neonatal hypotonia (6%) were much less frequent. With respect to developmental difficulties, the most common findings included clumsiness (87%), learning difficulties (87%), ataxia (83%), dysphagia (80%), and vertical gaze palsy (81%). Together, these findings confirm and extend previous reports investigating the clinical features associated with NPC1 disease.

Homology between Egg White Sulfhydryl Oxidase and Quiescin Q6 Defines a New Class of Flavin-linked Sulfhydryl Oxidases

The flavin-dependent sulfhydryl oxidase from chicken egg white catalyzes the oxidation of sulfhydryl groups to disulfides with the reduction of oxygen to hydrogen peroxide. Reduced proteins are the preferred thiol substrates of this secreted enzyme. The egg white oxidase shows an average 64% identity (from randomly distributed peptides comprising more than 30% of the protein sequence) to a human protein, Quiescin Q6, involved in growth regulation. Q6 is strongly expressed when fibroblasts enter reversible quiescence (Coppock, D. L., Cina-Poppe, D., Gilleran, S. (1998)Genomics 54, 460–468). A peptide antibody against Q6 cross-reacts with both the egg white enzyme and a flavin-linked sulfhydryl oxidase isolated from bovine semen. Sequence analyses show that the egg white oxidase joins human Q6, bone-derived growth factor, GEC-3 from guinea pig, and homologs found in a range of multicellular organisms as a member of a new protein family. These proteins are formed from the fusion of thioredoxin and ERV motifs. In contrast, the flavin-linked sulfhydryl oxidase from Aspergillus niger is related to the pyridine nucleotide-dependent disulfide oxidoreductases, and shows no detectable sequence similarity to this newly recognized protein family.

Generating Disulfides in Multicellular Organisms: Emerging Roles for a New Flavoprotein Family

Peptides and proteins destined for secretion in multicellular organisms usually contain disulfide bonds, from small peptides tomassive extracellular matrix (ECM)2 proteins with hundreds of disulfide bridges. Disulfides are important to the structure, stability, and regulation of many proteins having at least one extracellular domain; they are critical to the formation and remodeling of the ECM and other disulfide networks, and they are crucial elements in various redox signaling pathways. However, the pathways for their biosynthesis in multicellular organisms remain surprisingly cryptic.We do not really knowhow a single protein disulfide bond is introduced in any metazoan, green plant, or protist. Why is our understanding of oxidative folding in so rudimentary a state? One reason is the very reactivity of thiolate nucleophiles and the degeneracy of pathways for the interconversion of thiols and disulfides. A second factor is the facile non-enzymatic oxidation of thiols by a number of potential cellular oxidants including GSSG (1). A third issue is the commonmisperception that oxygen is a facile oxidant of juxtaposed thiols, a reaction that is spin-forbidden and strongly catalyzed by traces of redox-active transitionmetal ions (notably copper and iron). Finally, multicellular organisms have additional pathways for disulfide bond formation that are not shared with the genetically tractable yeast systems.

Systems approaches to the networks of aging

The aging of an organism is the result of complex changes in structure and function of molecules, cells, tissues, and whole body systems. To increase our understanding of how aging works, we have to analyze and integrate quantitative evidence from multiple levels of biological organization. Here, we define a broader conceptual framework for a quantitative, computational systems biology approach to aging. Initially, we consider fractal supply networks that give rise to scaling laws relating body mass, metabolism and lifespan. This approach provides a top-down view of constrained cellular processes. Concomitantly, multi-omics data generation build such a framework from the bottom-up, using modeling strategies to identify key pathways and their physiological capacity. Multiscale spatio-temporal representations finally connect molecular processes with structural organization. As aging manifests on a systems level, it emerges as a highly networked process regulated through feedback loops between levels of biological organization.

Primary cultured fibroblasts derived from patients with chronic wounds: a methodology to produce human cell lines and test putative growth factor therapy such as GMCSF

BackgroundMultiple physiologic impairments are responsible for chronic wounds. A cell line grown which retains its phenotype from patient wounds would provide means of testing new therapies. Clinical information on patients from whom cells were grown can provide insights into mechanisms of specific disease such as diabetes or biological processes such as aging.The objective of this study was 1) To culture human cells derived from patients with chronic wounds and to test the effects of putative therapies, Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) on these cells. 2) To describe a methodology to create fibroblast cell lines from patients with chronic wounds.MethodsPatient biopsies were obtained from 3 distinct locations on venous ulcers. Fibroblasts derived from different wound locations were tested for their migration capacities without stimulators and in response to GM-CSF. Another portion of the patient biopsy was used to develop primary fibroblast cultures after rigorous passage and antimicrobial testing.ResultsFibroblasts from the non-healing edge had almost no migration capacity, wound base fibroblasts were intermediate, and fibroblasts derived from the healing edge had a capacity to migrate similar to healthy, normal, primary dermal fibroblasts. Non-healing edge fibroblasts did not respond to GM-CSF. Six fibroblast cell lines are currently available at the National Institute on Aging (NIA) Cell Repository.ConclusionWe conclude that primary cells from chronic ulcers can be established in culture and that they maintain their in vivo phenotype. These cells can be utilized for evaluating the effects of wound healing stimulators in vitro.

Delineation of the breakpoints of pure duplication 3q due to a de novo duplication event using SOMA

Delineation of the Breakpoints of Pure Duplication 3q Due to a De Novo Duplication Event Using SOMA A.L. Shanske,* J. Leonard, O. Nahum, D.L. Coppock, and B. Levy Center for Craniofacial Disorders, Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York Coriell Institute for Medical Research, Camden, New York Department of Pathology, Columbia University College of Physicians & Surgeons, New York, New York