Hydrophobic interactions are the prevalent force in bromelain:Fab' complex.
Antibromelain polyclonal antibodies against stem bromelain were raised in male albino rabbits and the Fab monomers isolated from the IgG of the immune sera as reported in our earlier communication (Gupta, P., Khan, R. H., and Saleemuddin, M. (2003) Biochim. Biophys. Acta, 1646, 131-135). Further, as evident from that communication bromelain:Fab complex has 1 : 1 stoichiometry. The stability of bromelain:Fab complex (1 : 1 stoichiometry) was investigated by far and near-UV CD and fluorescence measurements. Addition of up to 1.8 M NaCl caused no significant changes in fluorescence signals and near-UV CD peak pattern. However, the spectral studies together with gel filtration studies suggest dissociation of the complex beyond 5% (v/v) methanol. These results show that hydrophobic interactions play a pronounced role in the binding of Fab to bromelain while electrostatic interactions may be less crucial.
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, Uttar Pradesh 202002, India. pawan_g75@hotmail.com
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Gupta
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Saleemuddin
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Khan
D000818:Animals; D001963:Bromelains / Q000737:chemistry* / Q000276:immunology; D002850:Chromatography, Gel / Q000379:methods; D002942:Circular Dichroism / Q000379:methods; D057927:Hydrophobic and Hydrophilic Interactions; D007140:Immunoglobulin Fab Fragments / Q000737:chemistry* / Q000276:immunology; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000276:immunology; D011485:Protein Binding / Q000276:immunology; D011817:Rabbits; D012965:Sodium Chloride / Q000737:chemistry
D007140:Immunoglobulin Fab Fragments; D046912:Multiprotein Complexes; D012965:Sodium Chloride; D001963:Bromelains; C091760:stem bromelain