Purification and characterisation of a C-S lyase in seeds of Parkia speciosa Hassk

Molan Zhang; Rishika Batra; Melita Brainta; Dejian Huang

doi:10.1016/j.foodchem.2022.134438

Purification and characterisation of a C-S lyase in seeds of Parkia speciosa Hassk

Food Chem. 2023 Mar 15;404(Pt A):134438. doi: 10.1016/j.foodchem.2022.134438. Epub 2022 Sep 28.

Authors

Molan Zhang¹, Rishika Batra², Melita Brainta³, Dejian Huang⁴

Affiliations

¹ Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117542, Singapore. Electronic address: e0511872@u.nus.edu.
² Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117542, Singapore. Electronic address: e0553979@u.nus.edu.
³ Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117542, Singapore. Electronic address: melita.brainta@u.nus.edu.
⁴ Department of Food Science and Technology, National University of Singapore, 2 Science Drive 2, Singapore 117542, Singapore; National University of Singapore (Suzhou) Research Institute, 377 Lin Quan Street, Suzhou Industrial Park, Jiangsu 215123, China.

PMID: 36444008
DOI: 10.1016/j.foodchem.2022.134438

Abstract

Organosulfides are responsible for the characteristic aroma of Parkia speciosa Hassk seeds (stink bean) yet its formation mechanism from the precursor djenkolic acid has not been characterized. Herein, the aqueous extracts of stink bean were analysed by LC/MS, and the volatile components were extracted and analysed by GC/QTOF/MS. Using enzyme purification methods, we isolated and characterized C-S lyase from ripe stink beans. The active C-S lyase is composed of two protein subunits with molecular weights of 58 kDa and 45 kDa and forms agglomerates in solution with an average particle size of ∼ 50 nm. The enzyme was stable at pH 7.0-11.0 with an optimal pH ∼ 9.0 and was more stable at 25-40 °C with an optimal activity at 50 °C. It shows high substrate specificity towards l-cystine and l-djenkolic acid by forming methanedithiol, which leads to the formation of 1,2,4-trithiolane. C-S lyase is a promising biocatalyst for natural flavour production.

Keywords: C-S lyase; Cyclic organosulfides; Djenkolic acid; Enzyme purification; Parkia speciousa.

MeSH terms

Cysteine
Fabaceae*
Seeds

Substances

carbon-sulfur lyase
djenkolic acid
Cysteine