Biochemical Characterization of a Cold-Adapted λ-Carrageenase OUC-CglA from Maribacter vaceletii: An Efficient Tool for λ-Carrageenan Degradation

Abstract

λ-Carrageenase with high activity is an effective and environmentally friendly tool enzyme for the preparation of λ-carrageenan oligosaccharides with various biological activities. Herein, a novel GH150 (glycoside hydrolases family 150) λ-carrageenase OUC-CglA from Maribacter vaceletii was heterologously expressed, purified, and characterized. The recombinant OUC-CglA performs strict selectivity toward λ-carrageenan with a specific activity of 418.7 U/mg under its optimal reaction conditions of 20 °C and pH 7.0. Additionally, OUC-CglA is a typical cold-adapted λ-carrageenase because it unfolds 90% and 63% of its maximum activity at 15 and 10 °C, respectively. The hydrolysis process suggests that OUC-CglA is an endotype λ-carrageenase with the final products consisting of λ-neocarrabiose, λ-neocarratetraose, λ-neocarrahexaose, and other long-chain λ-neocarrageenan oligosaccharides. As a result, high activity, cold-adaptation, and principal products of OUC-CglA make it a potential biocatalyst for the effective preparation of λ-carrageenan oligosaccharides.

Identification and expression of MarCE, a marine carboxylesterase with synthetic ester‐degrading activity

“…To date, the majority of published work on the genus Maribacter has been related to the description of new species, the deposition of genomic sequences or their interactions with macroalgae, but with only a small number of Maribacter spp. enzymes being specifically characterized, primarily for their ability to degrade polysaccharides (Lee et al., 2016 ; Lu et al., 2022 ). To our knowledge, there are no reports describing other types of enzymes from Maribacter species, for example, those with activity towards ester and polyester substrates.…”

Characterization of a λ-Carrageenase Mutant with the Generation of Long-Chain λ-Neocarrageenan Oligosaccharides

“…The agarose, κ- and ι-carrageenan and were purchased from Sigma (St. Louis, MO, USA). The porphyran used for the substrate specificity determination was extracted in the same way as in the previous research [ 20 , 34 , 35 ]. the Escherichia coli DH5α was acquired from Tsingke Biotechnology Co., Ltd. (Beijing, China) and served as the cellular cloning host.…”

“…Some progress has been made in the enzymatic degradation of λ-carrageenan. Several λ-carrageenases have been found and characterized, and the ultimate products of these λ-carrageenases which have been reported until now, mostly consist of λ-neocarrabiose (Nλ2), λ-neocarratetraose (Nλ4) and λ-neocarrahexaose (Nλ6), and they are all short-chain oligosaccharides [ 17 , 18 , 19 , 20 , 21 , 22 ]. Therefore, more research studies into the preparation of long-chain λ-neocarrageenan oligosaccharides are essential.…”

“…In our previous study, a λ-carrageenase OUC-CglA from the marine bacterium M. vaceletii belonging to the glycoside hydrolase family 150 (GH150) was identified and characterized [ 20 ]. Notably, OUC-CglA, with a maximum specific activity of up to 418.68 U/mg, is a low-temperature-adapted enzyme whose product is mainly composed of short-chain oligosaccharides [ 20 ]. It was found that OUC-CglA has a pyrroloquinoline quinone (PQQ)-like helical folding region and its function has yet to be explored [ 20 ].…”

“…Notably, OUC-CglA, with a maximum specific activity of up to 418.68 U/mg, is a low-temperature-adapted enzyme whose product is mainly composed of short-chain oligosaccharides [ 20 ]. It was found that OUC-CglA has a pyrroloquinoline quinone (PQQ)-like helical folding region and its function has yet to be explored [ 20 ].…”