The proposed research concerns cellular mechanisms underlying chronic toxicity of organophosphonates that arise either as a primary consequence of acetylcholinesterase (AchE) inhibition or through mechanisms independent of AchE inhibition. In vitro studies employing primary cultures of embryonic chick skeletal muscle and neural retina and in vivo studies in rat will investigate organophosphonate-induced disruption in coupling of protein synthesis and secretion; these studies will focus on the effects exerted by organophosphorus agents on protein turnover (synthesis/degradation), post-translational oligosaccharide processing, and transmembrane signaling (changes in pH and Ca++). These studies are connected by a common theme that organophosphonates can alter protein turnover through either inhibition of intracellular proteinases, thereby prolonging degradation, or through mobilization of intracellular Ca++, thereby activating proteinases and accelerating protein degradation. To distinguish between these distinct and opposit effects, the proposed studies will employ chiral and achiral, charged and uncharged, fluorescent and non-fluorescent methylphosphonates, as well as a number of readily available Ca++- and pH-selective fluorescent dyes (QUIN2, FURA2, BCECF) and calcium channel antagonists. Finally, we plan to extend our ongoing in vivo studies of organophosphonate-induced alterations in cardiovascular function by examining stereospecificity of the hypertensive response induced (in rat) by enantiomeric organophosphorus agents; examination of subsequent aging and oxime reversal will afford a means for assessing the capacity for aging to occur in vivo and the requirement for oxime efficacy to arise from direct interaction with acetylcholinesterase.

National Institute of Health (NIH)
National Institute of Environmental Health Sciences (NIEHS)
Research Project (R01)
Project #
Application #
Study Section
Toxicology Subcommittee 2 (TOX)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
State University of New York at Buffalo
Schools of Pharmacy
United States
Zip Code
Joshi, Anil K; Witkowski, Andrzej; Berman, Harvey A et al. (2005) Effect of modification of the length and flexibility of the acyl carrier protein-thioesterase interdomain linker on functionality of the animal fatty acid synthase. Biochemistry 44:4100-7
Luo, Zhigang David; Berman, Harvey Alan (2004) Pb2+-mediated down-regulation of dihydropyridine receptors in skeletal muscle. Toxicol Lett 152:167-73
Wong, L; Radic, Z; Bruggemann, R J et al. (2000) Mechanism of oxime reactivation of acetylcholinesterase analyzed by chirality and mutagenesis. Biochemistry 39:5750-7
Taylor, P; Hosea, N A; Tsigelny, I et al. (1997) Determining ligand orientation and transphosphonylation mechanisms on acetylcholinesterase by Rp, Sp enantiomer selectivity and site-specific mutagenesis. Enantiomer 2:249-60
Luo, Z D; Berman, H A (1997) The influence of Pb2+ on expression of acetylcholinesterase and the acetylcholine receptor. Toxicol Appl Pharmacol 145:237-45
Hosea, N A; Radic, Z; Tsigelny, I et al. (1996) Aspartate 74 as a primary determinant in acetylcholinesterase governing specificity to cationic organophosphonates. Biochemistry 35:10995-1004
Jo, S A; Higgins, D M; Berman, H A (1992) Regulation of acetylcholinesterase in avian heart. Studies on ontogeny and the influence of vagotomy. Circ Res 70:633-43
Berman, H A; Leonard, K (1992) Interaction of tetrahydroaminoacridine with acetylcholinesterase and butyrylcholinesterase. Mol Pharmacol 41:412-8
Nowak, M W; Berman, H A (1991) Fluorescence studies on the interactions of myelin basic protein in electrolyte solutions. Biochemistry 30:7642-51
Decker, M M; Berman, H A (1990) Denervation-induced alterations of acetylcholinesterase in denervated and nondenervated muscle. Exp Neurol 109:247-55

Showing the most recent 10 out of 21 publications