Developmental regulation of proteoglycan synthesis and decorin expression during turkey embryonic skeletal muscle formation.

To delineate the role of proteoglycans in turkey skeletal muscle development, proteoglycan expression was examined in pectoral muscle from 14-, 20-, and 25-d-old embryos. Proteoglycans were separated by DEAE (diethylaminoethyl cellulose) anion exchange and molecular sieve chromatography. Glycosaminoglycan composition was measured by enzyme digestion and nitrous acid deamination. The proteoglycan decorin was analyzed at each of these stages of development for core protein size by polyacrylamide gel electrophoresis and for spatial distribution by immunohistochemistry. Chondroitin sulfate-containing proteoglycans were the predominant proteoglycans found throughout turkey embryonic skeletal muscle development. However, in 20- and 25-d-old pectoral muscle, higher levels of heparan and dermatan sulfate were observed compared with their values at 14 d. Two decorin core protein bands with molecular weights of 45 and 46 kDa were detected. Immunostaining for decorin showed that, as the connective tissue layers developed, decorin was localized in the perimysium and epimysium. These data indicate that turkey embryonic skeletal muscle proteoglycan expression is dynamic and changes from a matrix that is rich in a large chondroitin sulfate proteoglycan to one containing dermatan sulfate, heparan sulfate, and chondroitin sulfate proteoglycans, and suggests the presence of two forms of decorin.

Sulfated glycosaminoglycans and collagen in two bovine muscles (M. Semitendinosus and M. Psoas major) differing in texture.

M. semitendinosus (ST) and M. psoas major (PM) were used as models for tough and tender meat to study a possible role of sulfated glycosaminoglycans (GAGs) for muscle tenderness. The difference in texture was confirmed by Warner Bratzler shear force measurements. No significant difference in total amount of GAGs in the muscles was found. In contrast, a significant difference in the ratio of GAG/collagen was found between the two muscles. After separation of the GAGs by density gradient ultracentrifugation and ion-exchange chromatography, dermatan sulfate (DS), keratan sulfate (KS), chondroitin sulfate (CS), and heparan sulfate (HS) were identified by cellulose acetate electrophoresis after use of specific enzymes and chemical methods. The content of DS was higher in the tougher muscle (ST) than in PM, and the difference in DS content was statistically significant. Furthermore, a significant difference in the GAG composition pattern of the two muscles was found. The yield of GAGs extracted from the muscles was 77% for ST and 87% for PM. The residue after extraction was further analyzed and found to contain mainly HS. Immunohistochemical studies using antibodies against CS/DS showed a staining pattern of the perimysium of ST different from that of PM.

Decorin and a large dermatan sulfate proteoglycan in bovine striated muscle.

Proteoglycans were extracted and isolated from adult bovine muscle tissue by dissociative extraction followed by density gradient centrifugation, gel chromatography and ion-exchange chromatography. Two proteoglycans were characterized; one of large molecular size (PG-L) and one of small molecular size (PG-S). The recovery of PG-L and PG-S was 33% and 67%, respectively. By cellulose acetate electrophoresis before and after treatment with chondroitinase AC and ABC both samples were shown to carry predominantly dermatan sulfate chains. The large proteoglycan was recognized with an antibody against a large dermatan sulfate proteoglycan from bovine sclera, whereas the small was recognized by an antibody against decorin from bovine sclera. Chondroitinase ABC treatment of PG-S followed by SDS-PAGE showed a core protein with a molecular weight of 45 kDa, which also reacted with the decorin antibody. Amino-acid analysis of both PG-L and PG-S revealed an amino-acid composition closely similar, although not identical, to the large dermatan sulfate proteoglycan from bovine sclera and decorin, respectively. Immunohistochemical analyses of muscle tissue sections showed that decorin and the large dermatan sulfate proteoglycan are present in the perimysium layers of muscle tissue, although although with a somewhat different pattern of distribution. Decorin was, in addition, found in the endomysium.

Glucosyltransferase activity in human in vivo formed enamel pellicle and in whole saliva.

Two hour in vivo formed enamel pellicle samples and paraffin wax-stimulated saliva samples were collected from 10 volunteers for analyses of glycosyltransferase activity (GTF). GTF activity was recorded by monitoring incorporation of radioactivity from 14C-glucose labeled sucrose into glucan. Pellicle and saliva samples from all 10 subjects demonstrated GTF activity. The GTF activity in the pellicle samples was highest in subjects with high GTF activity producing adhesive glucan in saliva.

Purification of a protein component in extracts from supragingival dental calculus.

In the present study supragingival dental calculus of unknown age was collected from the mandibular incisors of three individuals and solubilized by EDTA. The extracts were examined by gel filtration, ionic exchange chromatography and amino acid analysis. A protein component with similar characteristics to the main protein component of the acquired enamel pellicle was a regular constituent of the calculus extracts from the three subjects.

Further studies on the composition of the acquired enamel pellicle.

In the present study pellicle material was collected from human teeth 2, 4 and 6 hr after cleaning. The material obtained was examined by gel filtration, ion exchange chromatography on CM-Sephadex and DEAE-Sephadex with subsequent amino acid analyses of the major anionic component. No major changes were observed to occur either in the overall composition or in the main anionic component of the pellicle during the first 6 hr.

Surface properties of fluoride treated hydroxyapatite as judged by interactions with albumin and lysozyme.

Hydroxyapatite treated with fluoride containing both alkali soluble fluoride (CaF2) and alkali stable fluoride (FAp) was shown to take up less albumin than hydroxyapatite but more lysozyme. The affinity of the adsorption of albumin to fluoride treated apatite was increased, whereas no difference was demonstrated in the affinity of lysozyme. Tooth surfaces in vivo contain both calcium fluoride and fluoroapatite. Protein adsorption to mixed phases may thus have clinical significance.

Gel filtration, ion exchange chromatography and chemical analysis of macromolecules present in acquired enamel pellicle (2-hour-pellicle).

Proteins obtained from the surface of human teeth in vivo were solubilized in EDTA and subjected to gel permeation, ionic exchange chromatography and amino acid analysis. It was found that the main component was anionic and was eluted between albumin and lysozyme on Sepharose. It contained abundant amounts of serine, glycine and glutamic acid. A salivary phosphoprotein of similar amino acid composition has previously been purified.