Distinct streptomycetes such as Streptomyces mobaraensis produce the protein cross-linking enzyme transglutaminase. Bioinformatic analysis predicted the occurrence of seven sortases exerting transpeptidation reactions similarly to transglutaminase. Here, we report the production and characterization of sortase E2 (Sm-SrtE2) solubilized by removal of its membrane anchor domain. Sm-SrtE2 activity was measured using pentapeptides predicted to be cell wall sorting signals of putative sortase substrate proteins. Preferred linkage to Gly by Sm-SrtE2 was in the order LAETG>>LAHTG>>LAQTG~LANTG>LARTG. Chaplin 1 from S. mobaraensis was further demonstrated to be an excellent substrate of both the intrinsic Sm-SrtE2 and transglutaminase. The unexpected discovery showing Gln-62 and Gln-65 of Δ -Sm-SrtE2 as transglutaminase cross-linking sites suggests that low enzyme stability might be due to anchor domain truncation and a disordered N terminus.
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http://dx.doi.org/10.1002/1873-3468.13466 | DOI Listing |
Int J Biol Macromol
January 2025
College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China. Electronic address:
To elucidate the effect of transglutaminase (TG) on the rheological properties of wheat gluten, this study investigates the underlying mechanisms by analyzing changes in gluten structure. The results demonstrated that the TG-treated gluten samples had higher storage modulus (G') and loss modulus (G″) compared to the control, conversely, creep and recovery strains followed an opposite trend. Notably, the most pronounced effects were observed with adding 2 U/g TG for 20-30 min.
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December 2024
Department of Functional Food Product Development, Wroclaw University of Environmental and Life Sciences, 37 Chelmonskiego Str., 51-630 Wroclaw, Poland.
With growing environmental and health concerns surrounding meat consumption, meat analogs have emerged as sustainable and health-conscious alternatives. A major challenge in developing these products is replicating the fibrous, elastic texture of meat, where microbial transglutaminase (MTG) has shown significant potential. MTG catalyzes protein cross-linking, enhancing the structural integrity of meat analogs.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China; Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China; National Research and Development Branch Center for Shellfish Processing (Zhanjiang), Zhanjiang 524088, China; Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety, Guangdong Provincial Engineering Technology Research Center of Seafood, Zhanjiang 524088, China. Electronic address:
This study aimed to investigate the structural characteristics of Stichopus horrens collagen (SHC), Holothuria scabra collagen (HSC), and Holothuria leucospilota collagen (HLC) and to assess the effect of transglutaminase (TGase) on their film-forming properties. The results indicated that the collagens from three species of sea cucumbers were type I collagen with a complete triple helical structure. The thermal denaturation temperature of HLC (34.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address:
In this work, six bovine bone gelatin (type B) samples with varying molecular weight (MW) fractions, comprising α-chains, high- and low-MW fractions, were prepared using ethanol precipitation and pH adjustment. The influence of molecular weight distribution (MWD) on gelatin gel strength was examined, along with the effects of these different MW fractions on microbial transglutaminase (MTGase) cross-linking gelatin. The results showed that, without MTGase treatment, high-MW fractions acted as key fillers in the formation of gelatin gel networks, while α-chains and their aggregates played a central role.
View Article and Find Full Text PDFPhytopathology
January 2025
Swedish University of Agricultural Sciences, Plant Protection Biology, Alnarp, Sweden;
Transglutaminases (TGases) are enzymes highly conserved among prokaryotic and eukaryotic organisms, where their role is to catalyze protein cross-linking. One of the putative TGases of has previously been shown to be localized to the cell wall. Based on sequence similarity we were able to identify six more genes annotated as putative TGases and show that these seven genes group together in phylogenetic analysis.
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