Sublethal doses of neonicotinoid imidacloprid can interact with honey bee chemosensory protein 1 (CSP1) and inhibit its function.
As a frequently used neonicotinoid insecticide, imidacloprid can impair the chemoreceptive behavior of honey bees even at sublethal doses, while the physiochemical mechanism has not been further revealed. Here, multiple fluorescence spectra, thermodynamic method, and molecular docking were used to study the interaction and the functional inhibition of imidacloprid to the recombinant CSP1 protein in Asian honey bee, Apis cerana. The results showed that the fluorescence intensity (λem= 332 nm) of CSP1 could be significantly quenched by imidacloprid in a dynamic mode. During the quenching process, ΔH > 0, ΔS > 0, indicating that the acting forces of imidacloprid with CSP1 are mainly hydrophobic interactions. Synchronous fluorescence showed that the fluorescence of CSP1 was mainly derived from tryptophan, and the hydrophobicity of tryptophan decreased with the increase of imidacloprid concentration. Molecular docking predicted the optimal pose and the amino acid composition of the binding process. Circular dichroism (CD) spectra showed that imidacloprid reduced the α-helix of CSP1 and caused the extension of the CSP1 peptide chain. In addition, the binding of CSP1 to floral scent β-ionone was inhibited by nearly 50% of the apparent association constant (KA) in the presence of 0.28-2.53 ng/bee of imidacloprid, and the inhibition rate of nearly 95% at 3.75 ng/bee of imidacloprid at sublethal dose level. This study initially revealed the molecular physiochemical mechanism that sublethal doses of neonicotinoid still interact and inhibit the physiological function of the honey bees' chemoreceptive system.
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China. Electronic address: atcjlu@126.com.
Hongliang
H
Li
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China.
Jing
J
Tan
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China.
Xinmi
X
Song
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China.
Fan
F
Wu
Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, PR China.
Mingzhu
M
Tang
Jinhua Academy of Agricultural Science, Jinhua 321000, PR China.
Qiyun
Q
Hua
College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China.
Huoqing
H
Zheng
College of Animal Sciences, Zhejiang University, Hangzhou 310058, PR China.
Fuliang
F
Hu
D000595:Amino Acid Sequence; D000818:Animals; D001516:Bees / Q000187:drug effects / Q000502:physiology; D018678:Cholinergic Agents / Q000737:chemistry / Q000633:toxicity*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology; D015870:Gene Expression; D007093:Imidazoles / Q000737:chemistry / Q000633:toxicity*; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007306:Insecticides / Q000737:chemistry / Q000633:toxicity*; D007700:Kinetics; D062105:Molecular Docking Simulation; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000737:chemistry / Q000633:toxicity*; D045792:Norisoprenoids / Q000037:antagonists & inhibitors / Q000737:chemistry*; D000072417:Protein Domains; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics; D014364:Tryptophan / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism
D018678:Cholinergic Agents; D007093:Imidazoles; D019476:Insect Proteins; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D045792:Norisoprenoids; D011994:Recombinant Proteins; C082359:imidacloprid; D014443:Tyrosine; D014364:Tryptophan; C008157:beta-ionone
Apis cerana; Binding interaction; Chemosensory protein; Functional inhibition; Neonicotinoid imidacloprid