2006 ที่น้องแอนทำ.pmd - Mahidol University

Mahidol University Abstract of International Publications 2006
No.95
Author(s) : Boonsanongchokying C, Sang – oum W, Sithigomgul P, Sriurairatana S, Flegel TW.
Title : Production of monoclonal antibodies to polyhedrin of Monodon Baculovirus (MBV)
from shrimp.
Source : ScienceAsia. 32 (4): 371 – 376, 2006 (Dec).
Document Type : Article.
Keywords : MBV, Monoclonal antibodies, Monodon baculovirus, Polyhedrin.
Abstract : Monodon baculovirus (MBV) is a member of the nucleopolyhedrosis virus (NPV)
group that produces polyhedral protein occlusion bodies that contain virions in epithelial
cells of the hepatopancreas of the peinaeid shrimp Penaeus monodon. The major
constituent protein of occlusion bodies is polyhedrin. Polyhedrin protein of MBV was
extracted from the infected hepatopancreas of P. monodon post larvae by hydroforce
and partially purified using Urografin gradient ultracentrifugation. A fraction at 50%
Urografin was examined by electron microscopy and shown to be dominated by
polyhedrin protein particles of 20 – 23 nm diameters. By SDS – PAGE, this fraction
yielded a single protein band at a molecular weight of 58 kDa corresponding to the
published size of MBV polyhedrin. This fraction was used to produce 17 monoclonal
antibodies (MAb) that were specific to MBV and without cross – reactivity to other
common shrimp viruses (i.e, hepatopancreatic parvovirus or HPV, yellow head virus
or YHV and white spot syndrome virus or WSSV) by immunohistochemistry. These
antibodies could be used to detect purified – polyhedrin with high sensitivity up to 0.2
g/ml by dot blot immunoassay. These MAb are candidates for sensitive MBV
immunodetection methods.
No.96
Author(s) : Boonserm P, Mo M, Angsuthanasombat C, Lescar J.
Title : Structure of the functional form of the mosquito larvicidal Cry4Aa toxin from Bacillus
thuringiensis at a 2.8 – Angstrom resolution.
Source : Journal of Bacteriology. 188 (9): 3391 – 3401, 2006 (May).
Document Type : Article.
Keywords : Manduca – sexta aminopeptidase, Receptor – binding domain, Delta – endotoxin,
Insecticidal toxin, Crytal – Stracture, Alpha – 4 – alpha – 5 loop, Spodoptera – exigua,
Subsp. israelensis, Escherichia – coli, CryIA (c) toxin.
Abstract : The Cry4Aa delta – endotoxin from Bacillus thuringiensis is toxic to larvae of Culex,
Anopheles, and Aedes mosquitoes, which are vectors of important human tropical
diseases. With the objective of designing modified toxins with improved potency that
could be used as biopesticides, we determined the structure of this toxin in its
functional form at a resolution of 2.8 angstrom. Like other Cry delta – endotoxins,
the activated Cry4Aa toxin consists of three globular domains, a seven – alpha – helix
bundle responsible for pore formation (domain I) and the following two other domains
having structural similarities with carbohydrate binding proteins: a beta – prism
(domain II) and a plant lectin – like beta – sandwich (domain III). We also studied the
effect on toxicity of amino acid substitutions and deletions in three loops located at
the surface of the putative receptor binding domain II of Cry4Aa. Our results indicate
that one loop is an important determinant of toxicity, presumably through attachment
of Cry4Aa to the surface of mosquito cells. The availability of the Cry4Aa structure
should guide further investigations aimed at the molecular basis of the target specificity
and membrane insertion of Cry endotoxins.
No.97
Author(s) : Boonserm P, Moonsom S, Boonchoy C, Promdonkoy B, Parthasarathy K, Torres J.
Title : Association of the components of the binary toxin from Bacillus sphaericus in solution
and with model lipid bilayers.
Source : Biochemical and Biophysical Research Communications. 342(4): 273–1278, 2006 (Apr).
Document Type : Article.
Keywords : Infrared spectroscopy, Binary toxin, Membranes, Mechanism, Insertion, Circular
dichroism.
Abstract : We show herein that interaction in aqueous solution of the two components of binary
toxin from Bacillus sphaericus, BinA and BinB, leads to a dramatic conformational
change, from beta turns or randorn coil, to beta structure. Also, either BinA or BinB
separately or their equimolar mixture, interact with lipid bilayers resulting in further
conformational changes. Upon membrane association, the change in conformation
observed for BinA or BinB separately is different from that observed when the
proteins are combined, indicating that proper folding depends oil the presence of the
complementary subunit. We also show, in contrast to previous reports, that BinB, but
not BinA, is able to insert in model neutral lipid monolayers.
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