Eugene R. Wiley

Species variation in the cross-linking characteristics of collagen from the intramuscular connective tissues of striated muscles (Bos taurus, Ovis aries, Sus scrofa)

1. 1. The intra- and intermolecular cross-linking characteristics of collagen isolated from the intramuscular connective tissues of ovine, bovine, and porcine l. dorsi muscles were investigated. 2. 2. Species differences in extent of synthesis and intermolecular cross-linking were observed. 3. 3. No difference in α/β ratio was found in the salt-soluble fractions, but bovine collagen had a significantly lower β12/ β11 ratio than ovine or porcine. 4. 4. In the acid-soluble fractions, porcine samples had 64 per cent dimer subunits, while ovine had 55 per cent and bovine 53 per cent. The greatest increase in the dimer content of the porcine samples was in the β12 fraction. 5. 5. The thermal shrinkage temperature of porcine muscle collagen was also significantly lower (P<0.01) than that from the other species. 6. 6. Only slight differences between species were found in amino-acid composition.

Amino-acid composition and cross-linking characteristics of collagen from intramuscular connective tissue of striated muscle (bos taurus

Abstract 1. 1. In samples representing 60–70 per cent of the total collagen from bovine semimembranosus muscle, the yields of salt- and acid-soluble collagen were 0.3 and 0.48 per cent, respectively. 2. 2. Collagen from muscle differed significantly from that of skin and tendon in solubility and distribution of cross-linked components. 3. 3. The component ratio of β 12 to β 11 was approximately 2: 1, indicating random crosslinking among the ai and α 2 -chains. 4. 4. The amino-acid composition of muscle collagen showed both similarities and differences when compared with either reticulin or skin and tendon collagens.

The effects of graded levels of dietary protein on collagen metabolism in the skin of growing rats

Abstract Male weanling rats were fed isocaloric diets containing from 10% to 45% casein, in steps of 5%, for three weeks. Maximum growth was observed in animals fed diets containing 25% or more casein and averaged twice as much weight gain as rats fed the 10% casein diet. The urinary excretion of hydroxyproline reflected growth and was low in the 10% casein-fed animals. The other diet groups whose weight gains were similar had similar urinary hydroxy-proline values. The in vitro synthesis of skin collagen revealed that diets of 20%, 25% and 30% casein stimulated the greatest rates of collagen synthesis at this age. The higher protein diets showed characteristics of collagen metabolism similar to low protein diets, probably due to the decrease in protein synthesis from the earlier high rates of synthesis in these animals. The effect of dietary protein level on collagen metabolism suggests that tissue development should be considered when growth is used as an indicator of protein nutritional status.

Isolation and characterization of type III collagen from bovine cardiac muscle.

Abstract 1. 1. Bovine cardiac muscle collagen was solubilized by limited digestion with pepsin and subsequently fractionated by differential salt precipitation. 2. 2. Chromatographie studies on CM-cellulose and agarose of pepsin-soluble collagen and its salt-precipitated fractions showed it to be composed of type I collagen and a species with a mol. wt of 285,000 daltons, having an amino acid composition characteristic of type III collagen. 3. 3. The molecular structure of the 285,000-dalton component was confirmed as [α1(III)]3 after reduction with dithiothreitol to a chains having the same amino acid composition. 4. 4. Cyanogen bromide peptides of pepsin-soluble collagen which co-eluted on CM-cellulose and were identified as α1(I)-CB8 and α1(III)-CB8 showed a molar ratio of 2:1 indicating that 25% of the collagen molecules solubilized are [α1(III)]3.

Isolation and characterization of papain solubilized collagen from bovine spinous process cartilage

Abstract 1. 1. The collagen from bovine spinous process cartilage was isolated after solubilization with papain at low temperature. 2. 2. Chromatographic studies on CM-cellulose revealed the presence of a single α chain in purified extracts from this source. 3. 3. The spinous process αl(II) chains had a mol. wt of 98,500 dallons, contained approx 3.4% carbohydrate with a molar ratio of galactose to glucose of 2.5:1 and had an aldehyde content of 0.28 /anole/ 100mg. 4. 4. The αl(II) chains contained 22 residues of hydroxylysine, 11 of which were substituted by hexose.