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Biochemistry

Title:		Binding conformation and kinetics of two pheromone-binding proteins from the Gypsy moth Lymantria dispar with biological and nonbiological ligands
Author(s):		Gong Y; Tang H; Bohne C; Plettner E;
Address:		"Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada"
Journal Title:		Biochemistry
Year:		2010
Volume:		49
Issue:		4
Page Number:		793 - 801
DOI:		10.1021/bi901145a
ISSN/ISBN:		1520-4995 (Electronic) 0006-2960 (Linking)
Abstract:		"Pheromone-binding proteins (PBPs) in insects can bind various substances and selectively deliver the message of a signal molecule to the downstream components of the olfactory system. This can be achieved either through a ligand-specific conformational change of the C-terminal peptide of the PBP or by selectively binding/releasing the ligand. PBP may also act as a scavenger to protect the sensory neurons from saturating at high ligand doses. We have compared two PBPs from the gypsy moth (PBP1 and PBP2) and their truncated forms (TPBPs), which lack the C-terminal peptide, in this study. Stopped-flow kinetics with N-phenyl-1-naphthylamine (NPN) have revealed a diffusion-controlled collisional step, between PBP and NPN, after which the NPN relocates into a hydrophobic environment. This work supports the hypothesis that binding between PBPs and ligands occurs stepwise. With the method of tryptophan fluorescence quenching, we have shown different local conformational changes around Trp 37, induced by different ligands, manifested in changes of both the steric and electronic environment around the residue. Importantly, we have noticed a significant difference in the changes induced by the biological ligand (the pheromone) and nonbiological ligands. Therefore, we hypothesize that PBP may serve a different function in each kinetic step, displaying a unique P.L conformation"
Keywords:		"Animals Carrier Proteins/*chemistry/*metabolism Insect Proteins/*chemistry/*metabolism Intercellular Signaling Peptides and Proteins Kinetics Ligands Models, Molecular Moths/metabolism Pheromones/chemistry/*metabolism Protein Conformation Structure-Activi;"
Notes:		"MedlineGong, Yongmei Tang, Hao Bohne, Cornelia Plettner, Erika eng Research Support, Non-U.S. Gov't 2009/12/19 Biochemistry. 2010 Feb 2; 49(4):793-801. doi: 10.1021/bi901145a"