RESUMO
A true isopycnic centrifugation method for the study of the bovine nasal cartilage proteoglycan polydispersity is presented. The use of cesium sulfate as gradient forming salt instead of cesium chloride allowed proteoglycan banding without any sedimentation at the bottom of the centrifuge tube. Apparent buoyant densities of proteoglycan monomer and proteoglycan aggregate were different. The present method provides a useful tool for the study of proteoglycan polydispersity and also allows us to follow the distribution of the link proteins in different proteoglycan extracts.
Assuntos
Proteoglicanas , Aminoácidos/análise , Animais , Carboidratos/análise , Bovinos , Centrifugação Isopícnica/métodos , Césio , Substâncias Macromoleculares , Proteoglicanas/isolamento & purificação , SulfatosRESUMO
Bovine nasal cartilage proteoglycan aggregates have been dissociated and separated by dissociative density gradient centrifugation into proteoglycan sub-units and "link fraction". The latter contained mainly the two "link proteins" as shown by analytical sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The two "link proteins" were then separated by preparative gel electrophoresis under dissociative conditions. Molecular weight and amino acid composition of both proteins are presented.
Assuntos
Cartilagem/análise , Proteínas/isolamento & purificação , Proteoglicanas , Aminoácidos/análise , Animais , Bovinos , Eletroforese em Gel de Poliacrilamida , Peso Molecular , NarizRESUMO
The N-terminal sequence (residues 1-101) of trypsin-link protein from cartilage proteoglycan complex is reported: it presents structural homologies with the poly-Ig receptor and immunoglobulin domains.
Assuntos
Proteínas da Matriz Extracelular , Imunoglobulinas/genética , Proteínas/genética , Proteoglicanas/genética , Sequência de Aminoácidos , Animais , Cartilagem/análise , Bovinos , Humanos , Polímeros , Receptores Imunológicos/genética , Homologia de Sequência do Ácido NucleicoRESUMO
Cyanogen bromide treatment of bovine nasal cartilage proteoglycan monomer gave rise to three major fractions (CN-1 to CN-3), isolated by Sepharose CL-6B chromatography. The uronate-rich fraction in the void volume (CN-1) digested with chondroitinase ABC (C treatment) yielded a fragment (CN-1 C/6B) with a unique N-terminal sequence. The same fraction, when digested sequentially by chondroitinase ABC and trypsin (CT treatment), was resolved into two distinct fractions, CN-1 CT/6B-1 and CN-1 CT/6B-2. CN-1 CT/6B-1 consisted in a keratan sulfate-rich region, representing the N-terminal moiety of the CN-1 fraction; these data suggested, according to the model of the proteoglycan monomer structure described by Heinegard, D. and Axelsson, I. (1977) J. Biol. Chem. 252, 1971-1979, that its C-terminal moiety is localized at the end of the core bearing the chondroitin sulfate chains. CN-1 CT/6B-2 contained two fragments from the chondroitin sulfate-bearing region: one of them has been submitted to Edman degradation. The CN-2 fraction upon chondroitinase and trypsin treatments gave rise to a keratan-bearing region (CN-2 CT/6B-1) and a mannose-rich region (CN-2 CT/6B-2). After reduction and alkylation of CN-2, the N-terminal sequence of the isolated major fragment (CN-2 RA/6B-1) was determined. The CN-3 fraction revealed a pattern upon electrophoresis similar to that of the cyanogen bromide-treated hyaluronic acid-binding region.
Assuntos
Cartilagem/análise , Proteoglicanas/isolamento & purificação , Sequência de Aminoácidos , Aminoácidos/análise , Animais , Bovinos , Brometo de Cianogênio , Substâncias Macromoleculares , Nariz , Fragmentos de Peptídeos/análiseRESUMO
SPOCK is prevalent in developing synaptic fields of the central nervous system (Charbonnier et al., 2000. Mech. Dev. 90, 317-321). The expression of SPOCK during neuromuscular junction (NMJ) formation was compared to agrin and acetylcholine receptor (AChR) distribution. SPOCK is detected within the myogenic masses during the early steps of embryonic development, and distributed in the cytoplasm of myotubes before coclustering with AChRs. In the adult, SPOCK is present in axons and is highly expressed by Schwann cells. SPOCK altered expression pattern after nerve lesioning, or cholinergic transmission blockade, strongly indicate that its cellular distribution at the NMJ depends on innervation.
Assuntos
Músculo Esquelético/embriologia , Junção Neuromuscular/embriologia , Junção Neuromuscular/crescimento & desenvolvimento , Proteoglicanas/genética , Proteoglicanas/metabolismo , Animais , Citoplasma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Camundongos , Camundongos Endogâmicos , Fibras Musculares Esqueléticas/fisiologia , Proteoglicanas/imunologia , Ratos , Ratos Sprague-Dawley , Receptores Colinérgicos/metabolismoRESUMO
SPOCK is a modular proteoglycan, with homology with proteins involved in cell adhesion processes and neurogenesis. We have previously shown that SPOCK transcripts predominate in the adult mouse brain. Here, we report its expression during mouse embryonic development by in situ hybridization, and immunocytochemistry. SPOCK is actively expressed at the onset of neurogenesis during periods of neuron migration and axonal outgrowth. At a later developmental stage, its expression is particularly prevalent within developing synaptic fields. In the peripheral nervous system, SPOCK expression is also developmentally regulated particularly in dorsal root ganglion neurons.
Assuntos
Desenvolvimento Embrionário e Fetal , Proteoglicanas/genética , Animais , Expressão Gênica , Camundongos , Sistema Nervoso/embriologia , Proteoglicanas/metabolismoRESUMO
The expression of the human serglycin gene was determined in nine human leukemic cell lines, representing a spectrum of erythrocytic, megakaryocytic, monocytic, granulocytic, and lymphocytic potentialities. By Northern blot analysis, a 1.4 kb transcript was characterized in some of these cell lines, using a cDNA probe coding for human serglycin. Five of these cell lines, HEL, U-937, HL-60, K-562, and KU-812 were treated with phorbol myristic acetate to induce differentiation. Under these conditions the expression of the serglycin gene was modulated compared to the non-induced cells. HL-60, K-562, and KU-812 were also induced with dimethyl sulfoxide and retinoic acid; variations in serglycin transcript level were also observed. The present investigation establishes, at the nucleic acid level, the ability of various cells mimicking different stages in the developmental pathways of the haemopoietic lineage to synthesize proteoglycans belonging to the serglycin family. The results reported here led us to conclude that serglycin expression is closely associated with the haemopoietic cell differentiation pathway. The putative functions of serglycin in the haemopoietic system are briefly discussed.
Assuntos
Leucemia/genética , Proteoglicanas/genética , Northern Blotting , Dimetil Sulfóxido/farmacologia , Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , RNA Mensageiro/genética , Acetato de Tetradecanoilforbol/farmacologia , Tretinoína/farmacologia , Células Tumorais Cultivadas , Proteínas de Transporte VesicularRESUMO
Structural homologies between link proteins and proteoglycan monomers are demonstrated. A possible redundancy in the proteoglycan monomers structure is discussed and the link proteins domains homologous to other proteins are specified.
Assuntos
Proteínas da Matriz Extracelular , Proteínas , Proteoglicanas , Serina Endopeptidases , Sequência de Aminoácidos , Cromatografia em Gel , Brometo de Cianogênio , Endopeptidases , Substâncias Macromoleculares , Fragmentos de Peptídeos , TripsinaRESUMO
The present report develops our previous structural data concerning the cyanogen bromide fragments from the bovine nasal cartilage proteoglycan monomers. Among the reported sequences a Met-Ile-Trp-His sequence was characterized, useful for future studies devoted to the molecular cloning of the proteoglycan monomers.
Assuntos
Cartilagem/análise , Proteoglicanas , Sequência de Aminoácidos , Animais , Bovinos , Cromatografia em Gel , Brometo de Cianogênio , Eletroforese em Gel de Poliacrilamida , Oligonucleotídeos , Fragmentos de PeptídeosRESUMO
The primary structure of a human platelet proteoglycan (P.PG) core was established by a combination of amino acid sequence analysis and cDNA cloning. The deduced 131 amino acid long protein contains eight Ser-Gly repeats. The significance of homologies observed between P.PG and promyelocytic leukemia cell line proteoglycans is discussed.
Assuntos
Plaquetas/análise , Proteoglicanas/sangue , Sequência de Aminoácidos , Sequência de Bases , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , DNA/genética , Humanos , Leucemia , Dados de Sequência Molecular , Proteoglicanas/genética , Sequências Repetitivas de Ácido Nucleico , Homologia de Sequência do Ácido Nucleico , Células Tumorais CultivadasRESUMO
The enzymatic properties of Asterias rubens and Nephthys hombergii lysozymes were compared with those of hen egg-white lysozyme. The results allowed to conclude that the Asterias rubens lysozyme was representative of a new lysozyme type. The Nephthys hombergii lysozyme however could be classified among the hen type enzymes with a tendency to exhibit under certain conditions some properties attributed to the goose type lysozymes.
Assuntos
Equinodermos/enzimologia , Muramidase/metabolismo , Poliquetos/enzimologia , Acetilglucosamina/farmacologia , Animais , Bacteriólise , Galinhas , Gansos , Micrococcus , Muramidase/antagonistas & inibidores , Concentração OsmolarRESUMO
Proteoglycans in male reproductive tract have been mainly characterized in testicular extracellular matrix and somatic cells. Heparan sulfate, chondroitin sulfate and hybrid chondroitin/heparan sulfate proteoglycans coexist within the testes. Their biological roles are not currently established, however, the molecular characterization of some of them is indicative that they might be involved in various regulatory processes during spermatogenesis.