Solubilization of type I and V collagens in Japanese flounder muscle during chilled storage

Abstract

The post-mortem changes of type I and V collagens in Japanese flounder muscle during chilled storage were examined. The muscle softened significantly within 12 h under chilled storage. Both type I and V collagens isolated by ion-exchange chromatographies showed no remarkable changes in band patterns even after 24 h of storage, suggesting that degraded collagen molecules may be removed from the collagen fraction by a conventional preparation method. In contrast, type I and V collagen molecules were detected by Western blotting with each specific antibody in a saline extract and gradually increased during chilled storage. These results suggest that both type I and V collagens may participate in the post-mortem softening of fish muscle.

Effects of different pre-salting methods on protein aggregation during heavy salting of cod fillets

“…Existence of a 47 kDa band has previously been reported for salted cod but not further identified (Martínez-Alvarez & Gómez-Guillén, 2006). In addition, proteolytic fragments of troponin (27, 22 and 18 kDa) and collagen (100-145 kDa (afraction) and 209 kDa (b-fraction)) may have been present (Kimiya et al, 2005;Shigemura, Ando, Harada, & Tsukamasa, 2004). Actin (42-45 kDa), tropomyosin (35-39 kDa) and the MLC (15-25 kDa), remained relatively unchanged during salting.…”

Involvement of MMP‐9 in collagen degradation of sea bass (Lateolabrax japonicus): Cloning, expression, and characterization

“…Five types of collagen, namely, I, III, IV, V, and VI are present in fish muscle (Bruggemann & Lawson, 2005), whereas type I and V collagens are the typical fibrillar collagens in the intramuscular connective tissues. Type I collagen can co‐assemble with type V collagen into heterotypic fibrils, which are the lower‐level structural elements of collagen fibers (Kimiya et al., 2005). The disintegrations of type I and V collagens were responsible for fish tenderness during chilled storage (Xu et al., 2015).…”

“…The entire triple‐helical domain of the type V collagen molecules is buried within the fibrils, and type I collagen molecules are present along the fibril surface (Birk, 2001). Type I and type V collagen may solubilize simultaneously and/or continuously during chilled storage (Kimiya et al., 2005). It was also suspected that MMP‐9 was involved in the muscle tenderization of sea bass during postmortem, so the degradation of rcMMP‐9 on type I and V collagens was then investigated.…”

“…Cleavage of all three chains of type V collagen by rcMMP‐9 was effective even at 4°C (Figure 3b). It has been suggested that the solubilization of type V collagen was supposed to be responsible for fish muscle softening during chilled storage (Kimiya et al., 2005; Xu et al., 2015).…”