Work

Identification of S-1-propenyl-L-cysteine as the catalytic product of AfGGT1 and a key intermediate in isoalliin biosynthesis in Allium fistulosum. L

Year: 2025

Type: article

Abstract: Our findings reveal that pyruvic acid content is generally higher in Allium fistulosum than in A. cepa . In A. fistulosum , the bulbs contain more pyruvic acid than the leaves, while in A. cepa , the inner bulb layers exhibit higher levels compared to the outer layers. We demonstrate that A. fistulosum γ-glutamyl transpeptidase 1 (AfGGT1) catalyzes the production of S-1-propenyl-L-cysteine from γ-glutamyl-S-1-propenylcysteine, whereas AfGGT2 and AfGGT3 lack catalytic activity. In natural populations of A. fistulosum , AfGGT1 expression shows a strong positive correlation with pyruvic acid content (R 2 = 0.6976). The optimal catalytic conditions for AfGGT1 are pH 7 and 37 °C, with a K m value of 0.2686 mM under these conditions. Molecular docking studies further reveal distinct substrate-binding conformations among AfGGT1, AfGGT2, and AfGGT3, highlighting functional divergence within the enzyme family. • AfGGT1 converts γ-glutamyl-S-1-propenylcysteine to S-1-propenyl-L-cysteine. • A. fistulosum is spicier than A. cepa , with its bulb spicier than its leaves. • Among the three AfGGTs, only AfGGT1 shows activity and stronger substrate binding.

Source: Food Chemistry Molecular Sciences

DOI: 10.1016/j.fochms.2025.100255

Authors: Mingzhao Zhu, Huanhuan Xu, Zhili Deng, Menglu Hou, Lecheng Liu, Yongqin Wang

Institutions: Beijing Academy of Agriculture and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Yangtze University

Language: English

Topic: Garlic and Onion Studies

Subfield: Plant Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,320