New insights into chlorophyll-WSCP (water-soluble chlorophyll proteins) interactions : The case study of BnD22 (Brassica napus drought-induced 22 kDa)

Bouargalne, Youssef ¹Raguenes-Nicol, Celine ¹Guilbaud, Florian ¹Cheron, Angelique ¹Clouet, Vanessa ¹Deleu, Carole ¹Le Caherec, Francoise¹

扫码查看

作者信息

1. Univ Rennes 1
折叠

Abstract

The water-soluble chlorophyll-proteins (WSCP) of class II from Brassicaceae are non-photosynthetic proteins that bind chlorophylls (Chls) and chlorophyll derivatives. Their physiological roles, biochemical functions and mode of action are still unclear. It is assumed that the WSCPs have a protection function against Chl photodamage during stressful conditions. WSCPs are subdivided into class IIA and class IIB according to their apparent Chla/b binding ratio. Although their Chla/Chlb binding selectivity has been partly characterized, their Chl affinities are not yet precisely defined. For instance, WSCPs IIA do not show any Chl binding preference while WSCPs IIB have greater affinity to Chlb. In this study, we present a novel method for assessment of Chl binding to WSCPs based on the differences of Chl photobleaching rates in a large range of Chl/protein ratios. The protein we have chosen to study WSCP is BnD22, a WSCP IIA induced in the leaves of Brassica napus under water deficit. BnD22 formed oligomeric complexes upon binding to Chla and/or Chlb allowing a protective effect against photodamage. The binding constants indicate that BnD22 binds with high affinity the Chls and with a strong selectivity to Chla. Moreover, dependending of Chl/protein ratio upon reconstitution, two distinct binding events were detected resulting from difference of Chl stoichiometry inside oligomeric complexes.

Key words

Chl binding constants/Photobleaching/Microscale thermophoresis/BINDING-PROTEIN/MOLECULAR-CLONING/INTRACELLULAR-LOCALIZATION/FUNCTIONAL EXPRESSION/PIGMENT-PIGMENT/INHIBITOR/STRESS/STABILITY/PLANTS

引用本文复制引用

出版年

2022

Plant Physiology and Biochemistry

SCI

ISSN：0981-9428

被引量2

参考文献量40

段落导航