Chemical modification of b-lactoglobulin by quinones

• Main Authors: DUSAN SLADIC, NENAD MILOSAVIC, NATASA BOZIC, TATJANA BOZIC, ZORAN VUJCIC, IRENA NOVAKOVIC
• Format: Article
• Language: English
• Published: Serbian Chemical Society 2003-05-01
• Series: Journal of the Serbian Chemical Society
• Subjects: avarone; quinone; b-lactoglobulin; covalent modification
• Online Access: http://www.shd.org.yu/HtDocs/SHD/Vol68/No4-5/V68-No4_5-01.pdf

The avarone/avarol quinone/hydroquinone couple, as well as their derivatives show considerable antitumor activity. In this work, covalent modifications of b-lactoglobulin, isolated from cow milk, by avarone, its model compound 2-tert-butyl-1,4-benzoquinone, and several of their alkylthio derivatives were studied. The techniques applied for assaying the modifications were: UV/VIS spectrophotometry, SDS PAGE and isoelectrofocusing. The results of the SDS PAGE suggest that polymerisation of the protein occurs. The shift of the pI of the protein upon modification toward lower values indicates that lysine amino groups are the principal site of the reaction of b-lactoglobulin with the quinones.