A Comparison of Cross-linking of Fish Myofibrillar Proteins by Endogenous and Microbial Transglutaminases

Abstract

The cross-linking reaction was performed in the medium containing fish myofibrillar proteins, 0.5 M (or 0.1 M) NaCl, and 5 mm CaCl2 at pH 7.5 and 25•Ž with transglutaminases from carp muscle and the culture filtrate of a strain of Streptoverticillium mobaraense. Carp enzyme (CTGase) preferentially polymerized myosin heavy chains among individual myofibrillar components. Microbial enzyme (MTGase) also rapidly cross-linked myosin heavy chains at different sites from those with CTGase. Con nectin (titin) was polymerized much faster than myosin heavy chain in soluble and aggregated states. The aggregated connectin was also cross-linked with CTGase at slow rate. Both enzymes could not cross-link actin molecules at all, though an amine (MDC) was incorporated to actin, suggesting the presence of active glutaminyl residue(s) as acyl donor. Using fluorescent probes, IAEDANS-labeled actin and myosin, it was revealed that they were cross-linked with connectin by the action of MTGase and consequently their heteropolymers with huge molecular mass were produced together with connectin homopolymers.

Gelling properties of white shrimp (Penaeus vannamei) meat as influenced by setting condition and microbial transglutaminase

“…Generally, shrimp meat has the poor gel forming ability, which is possibly associated with the low setting phenomenon or the inappropriate protein structure for cross-linking or gelation. Though MTGase has been successfully used for improving the gel property of various proteins including surimi (Nakahara, Nozawa, & Seki, 1999;Nonaka et al, 1989;Tanaka, Nonaka, & Motoki, 1990), no information regarding the use of MTGase in shrimp meat, especially from white shrimp, has been reported. The objective of this study was to investigate the influence of MTGase in combination with setting on the gel properties of white shrimp meat.…”

Improvement of Gelling Properties of Lizardfish Mince as Influenced by Microbial Transglutaminase and Fish Freshness

“…No marked changes in actin were obtained in the presence and absence of MTGase. Nakahara and others (1999) reported that MTGase and carp TGase could not cross‐link actin molecules. The decrease in MHC band intensity was concomitant with the increased breaking force and deformation (Figure 1).…”

Microbial Transglutaminase Catalyzed the Cross-Linking of Myofibrillar/Soy Protein Isolate Mixtures

“…Similar observations were reported by Nakahara et al . (), who revealed that MTGase preferentially cross‐linked connectin, followed by MHC, troponin T and actin, respectively. In contrast, no changes were found in the content of actin obtained from beef (Dondero et al .…”