Zeitschrift fur
Z. Lebensm. Unters.-Forsch. 164, 31
LebensmittelUntersuchung und-Forschung
33 (1977)
@ J. F. Bergmann-Verlag 1977
Properties of Insoluble Collagen from three Different Types of Muscles Olga Van~ikovfi 1 and Zden~k Deyl 2 Research Institute of Food Industry, Prague, Na B~lidle 21, 15038 Prague 5, CSSR 2 Czechoslovak Academy of Science, Institute of Physiology, Prague (Czechoslovakia)
Eigenschaften des unl~Jslichen Kollagens aus drei verschiedenen Muskeltypen Zusammenfassung. 1. Die lyotropische Solubilisierung von unl6slichem Kollagen des Herzmuskels, des M. longissimus dorsi und des M. semimembranosus zeigt Unterschiede der Polymerisierung der Strukturen an. Im M.semimembranosus und im Herzmuskel ist der Polymerisierungsgrad am h6chsten, im solubilisierten Anteil des M. longissimus dorsi k6nnen dagegen wesentliche Anteile von c~- und fi-Ketten unterschieden werden. 2. Alle polymeren Strukturen k6nnen durch Behandlung mit Pepsin und Dithiothreitol abgebaut werden. 3. Die Proportion des Kollagens vom Typus I zum Typus III. ist in verschiedenen Muskeln unterschiedlich. Das Kollagen vom Typus I bildet einen betr/ichtlichen Anteil des Kollagenkerns im M.longissimus dorsi und im Herzmuskel, im M.semimembranosus iiberwiegt das Kollagen vom Typus III.
Introduction It has been shown in the previous studies by McClain Eli that only minor variations are discernible in between CNBr-peptides derived from skin collagen and those derived from soluble muscle collagen. Other results of McClain et al. [1] reflect the different characteristics of collagen from various porcine muscles [2]. Although extremely important in the field of collagen chemistry, these results lack information on what are the characteristics of the insoluble collagen core in different bovine muscles. As a matter of fact, numerous studies have been devoted to the role of collagen in meat toughness without unequivocal conclusions [3, 4]. The present investigation is based on the recent finding of Chung and Miller [51, Miller et al. [6] and Epstein [7] about the existence of two types collagen in skin (collagen types I and III) and on the investigation of Bradley et al. [81 on the complexity of collagen types in different tissues. Collagen from three types of bovine muscles was subjected to detailed investigation from the viewpoint of the relative proportion of individual types of collagen described so far. Since these collagens play a dinstinctly different role in animal physiology, it may well be expected that their relative proportion in different muscles may be reflected in different properties of meat and meat products. Special attention in this respect should be paid to the collagen type I to type III ratio because of the different cross-linking mechanisms involved.
Materials and Methods Summary. 1. Lyotropic solubilization of insoluble collagen from heart, M. longissimus dorsi and M.semimembranosus offers differently polymerized structures. In M.semimembranosus and in heart muscle the degree of polymerization is the highest, whilst in the solubilized portion of M. longissimus dorsi considerable proportions of ~- and fl-chains can be observed. 2. All the polymeric structures can be broken down by pepsin and dithiothreitol treatment. 3. The proportion of collagen type I to III varies in different muscles. Collagen type I constitutes a considerable portion of the collagenous core in M. longissimus dorsi and in heart muscle, whilst in M.semimembranosus the predominating type is collagen type III.
Muscle samples and preparations of muscle collagen bovine muscles (heart, M.semimembranosus and M.longissimus dorsi) were obtained from a local slaughterhouse and cooled to 4 ° C immediately after removal from the animal. Muscle connective tissue was isolated according to the method of McClain [2]. For lyotropic solubilisation of collagen samples, the insoluble residue was extracted with 6M-urea at room temperature over a period of 24 h. Excess urea was removed by repeated exhaustive dialysis (six times 24 h). Epstein's procedure, pepsin digestion [71, was applied to solubilize the insoluble preparation. Twice-recrystalized pepsin (Worthington) 100 mg was dissolved in 200 ml of 0.4-M-acetic acid, 8 g of insoluble collagen was added, and the suspension was stirred at 18° C for 22 h. In some experiments 0.1 M-HCI was used instead of acetic acid. Undigested residue was removed by centrifugation, the supernatant liquid was filtered and precipitated twice by dialysis against 0.02M-Na2HPO4. Then, the supernatant liquid was dialysed against 0.5M-acetic acid containing 0.86N-NaC1. The precipitate obtained in the last dialysis step was dissolved in 0.1M-acetic
32
O. Van~ikovfi and Z. Deyh Collagen from three Different Types of Muscles
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Z. Lebensm. Unters.-Forsch. 164, 31
LebensmittelUntersuchung und-Forschung
33 (1977)
@ J. F. Bergmann-Verlag 1977
Properties of Insoluble Collagen from three Different Types of Muscles Olga Van~ikovfi 1 and Zden~k Deyl 2 Research Institute of Food Industry, Prague, Na B~lidle 21, 15038 Prague 5, CSSR 2 Czechoslovak Academy of Science, Institute of Physiology, Prague (Czechoslovakia)
Eigenschaften des unl~Jslichen Kollagens aus drei verschiedenen Muskeltypen Zusammenfassung. 1. Die lyotropische Solubilisierung von unl6slichem Kollagen des Herzmuskels, des M. longissimus dorsi und des M. semimembranosus zeigt Unterschiede der Polymerisierung der Strukturen an. Im M.semimembranosus und im Herzmuskel ist der Polymerisierungsgrad am h6chsten, im solubilisierten Anteil des M. longissimus dorsi k6nnen dagegen wesentliche Anteile von c~- und fi-Ketten unterschieden werden. 2. Alle polymeren Strukturen k6nnen durch Behandlung mit Pepsin und Dithiothreitol abgebaut werden. 3. Die Proportion des Kollagens vom Typus I zum Typus III. ist in verschiedenen Muskeln unterschiedlich. Das Kollagen vom Typus I bildet einen betr/ichtlichen Anteil des Kollagenkerns im M.longissimus dorsi und im Herzmuskel, im M.semimembranosus iiberwiegt das Kollagen vom Typus III.
Introduction It has been shown in the previous studies by McClain Eli that only minor variations are discernible in between CNBr-peptides derived from skin collagen and those derived from soluble muscle collagen. Other results of McClain et al. [1] reflect the different characteristics of collagen from various porcine muscles [2]. Although extremely important in the field of collagen chemistry, these results lack information on what are the characteristics of the insoluble collagen core in different bovine muscles. As a matter of fact, numerous studies have been devoted to the role of collagen in meat toughness without unequivocal conclusions [3, 4]. The present investigation is based on the recent finding of Chung and Miller [51, Miller et al. [6] and Epstein [7] about the existence of two types collagen in skin (collagen types I and III) and on the investigation of Bradley et al. [81 on the complexity of collagen types in different tissues. Collagen from three types of bovine muscles was subjected to detailed investigation from the viewpoint of the relative proportion of individual types of collagen described so far. Since these collagens play a dinstinctly different role in animal physiology, it may well be expected that their relative proportion in different muscles may be reflected in different properties of meat and meat products. Special attention in this respect should be paid to the collagen type I to type III ratio because of the different cross-linking mechanisms involved.
Materials and Methods Summary. 1. Lyotropic solubilization of insoluble collagen from heart, M. longissimus dorsi and M.semimembranosus offers differently polymerized structures. In M.semimembranosus and in heart muscle the degree of polymerization is the highest, whilst in the solubilized portion of M. longissimus dorsi considerable proportions of ~- and fl-chains can be observed. 2. All the polymeric structures can be broken down by pepsin and dithiothreitol treatment. 3. The proportion of collagen type I to III varies in different muscles. Collagen type I constitutes a considerable portion of the collagenous core in M. longissimus dorsi and in heart muscle, whilst in M.semimembranosus the predominating type is collagen type III.
Muscle samples and preparations of muscle collagen bovine muscles (heart, M.semimembranosus and M.longissimus dorsi) were obtained from a local slaughterhouse and cooled to 4 ° C immediately after removal from the animal. Muscle connective tissue was isolated according to the method of McClain [2]. For lyotropic solubilisation of collagen samples, the insoluble residue was extracted with 6M-urea at room temperature over a period of 24 h. Excess urea was removed by repeated exhaustive dialysis (six times 24 h). Epstein's procedure, pepsin digestion [71, was applied to solubilize the insoluble preparation. Twice-recrystalized pepsin (Worthington) 100 mg was dissolved in 200 ml of 0.4-M-acetic acid, 8 g of insoluble collagen was added, and the suspension was stirred at 18° C for 22 h. In some experiments 0.1 M-HCI was used instead of acetic acid. Undigested residue was removed by centrifugation, the supernatant liquid was filtered and precipitated twice by dialysis against 0.02M-Na2HPO4. Then, the supernatant liquid was dialysed against 0.5M-acetic acid containing 0.86N-NaC1. The precipitate obtained in the last dialysis step was dissolved in 0.1M-acetic
32
O. Van~ikovfi and Z. Deyh Collagen from three Different Types of Muscles
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II
I
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