title: Isolation and partial characterisation of immunoglobulin from southern bluefin tuna Thunnus maccoyii Castelnau.
abstract: Specific and total serum immunoglobulins were extracted by immunoaffinity, mannan-binding protein and Protein A affinity chromatography from southern bluefin tuna (Thunnus maccoyii Castelnau) immunised with rabbit IgG, and from non-immunised southern bluefin tuna. SDS-PAGE in 10% reducing gels revealed two heavy chains with molecular weights of approximately 74.6 +/- 1.3 kDa and 71.2 +/- 0.9 kDa, and two light chains with molecular weights of approximately 29 +/- 1.2 kDa and 28 +/- 1.0 kDa. Under non-reducing, but denaturing, conditions in 4% and 5% SDS-PAGE gels, a high molecular weight and a low molecular weight fraction were demonstrated. By gel filtration using Sephacryl HR 300 a molecular weight of 845 kDa, consistent with a tetramer, was obtained for the high molecular weight fraction, and a molecular weight of 168 kDa, consistent with a monomer, was obtained for the low molecular weight fraction. The extinction coefficient at A280 for the purified immunoglobulin (Ig) was determined to be 1.24. Tuna a-rabbit IgG Ig was reactive with all non-reduced mammalian IgG antigens tested, suggesting that common conformational antigenic determinants were recognised.
authors.affiliation: Tasmanian Aquaculture and Fisheries Institute, School of Aquaculture, Launceston, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Watts
authors.forename: B L
authors.initials: BL
authors.lastname: Munday
authors.forename: C M
authors.initials: CM
authors.lastname: Burke
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity / Q000662:veterinary; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D007074:Immunoglobulin G / Q000737:chemistry / Q000145:classification / Q000276:immunology / Q000302:isolation & purification; D007132:Immunoglobulin Isotypes / Q000737:chemistry / Q000302:isolation & purification; D007136:Immunoglobulins / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification*; D008970:Molecular Weight; D011817:Rabbits; D013045:Species Specificity; D014413:Tuna / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007136:Immunoglobulins