TY - JOUR
T1 - Biochemical characterization of biotype-specific esterases in the whitefly, Bemisia tabaci Genn (homoptera
T2 - Aleyrodidae)
AU - Coats, Susan A.
AU - Brown, J. K.
AU - Hendrix, Donald L.
PY - 1994/7
Y1 - 1994/7
N2 - Biochemical properties of the predominant esterases found in two distinct populations, presently considered to be different biotypes of the whitefly Bemisia tabaci, were investigated. General esterases, previously established as diagnostic markers on native polyacrylamide gels (PAGE) for the 'A' and 'B' biotypes, were characterized with respect to molecular masses, isoelectric points (pIs), isomeric relationships, and substrate specificities. One previously unidentified band in the 'B' biotype was detected on native gels when ethylenediaminetetracetic acid (EDTA) was added to gel buffers. In each of the 'A' and 'B' biotypes, 12 bands were resolved by isoelectric focusing (IEF), and had pIs ranging from 4.86 to 7.37, and 4.70 to 6.59, respectively. The two bands ('B'1 and 'B'2), used as diagnostic markers on native gels for the 'B' biotype, were identified as a single band (E7) with IEF. An analogous E7 band was resolved in the 'A' biotype with IEF, but corresponded to only one isomer (A6) on native gels. Results of substrate studies revealed most bands on IEF gels had carboxylesterase activity. The E7 esterase in each biotype was identified specifically as acetylcholinesterase (AChE). Ferguson plots revealed these E7 esterases of the 'A' and 'B' biotypes had equivalent charges, but different molecular masses, indicating they are size isomers. Two dimensional (2D) and IEF analyses confirmed this relationship.
AB - Biochemical properties of the predominant esterases found in two distinct populations, presently considered to be different biotypes of the whitefly Bemisia tabaci, were investigated. General esterases, previously established as diagnostic markers on native polyacrylamide gels (PAGE) for the 'A' and 'B' biotypes, were characterized with respect to molecular masses, isoelectric points (pIs), isomeric relationships, and substrate specificities. One previously unidentified band in the 'B' biotype was detected on native gels when ethylenediaminetetracetic acid (EDTA) was added to gel buffers. In each of the 'A' and 'B' biotypes, 12 bands were resolved by isoelectric focusing (IEF), and had pIs ranging from 4.86 to 7.37, and 4.70 to 6.59, respectively. The two bands ('B'1 and 'B'2), used as diagnostic markers on native gels for the 'B' biotype, were identified as a single band (E7) with IEF. An analogous E7 band was resolved in the 'A' biotype with IEF, but corresponded to only one isomer (A6) on native gels. Results of substrate studies revealed most bands on IEF gels had carboxylesterase activity. The E7 esterase in each biotype was identified specifically as acetylcholinesterase (AChE). Ferguson plots revealed these E7 esterases of the 'A' and 'B' biotypes had equivalent charges, but different molecular masses, indicating they are size isomers. Two dimensional (2D) and IEF analyses confirmed this relationship.
KW - Bemisia tabaci
KW - Biotypes
KW - Esterases
KW - Esterases acetylcholinesterase
KW - Whitefly
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U2 - 10.1016/0965-1748(94)90060-4
DO - 10.1016/0965-1748(94)90060-4
M3 - Article
SN - 0965-1748
VL - 24
SP - 723
EP - 728
JO - Insect Biochemistry and Molecular Biology
JF - Insect Biochemistry and Molecular Biology
IS - 7
ER -