Immunochemical Comparison of β-Lactoglobulins

Abstract

Summary The genetic variants of cow β-lactoglobulin are indistinguishable by Ouchterlony double diffusion and the quantitative precipitin test. They are distinguishable from each other by complement and micro-complement fixation tests. Goat and sheep β-lactoglobulins are identical to the cow β-lactoglobulin variants by the Ouchterlony test, but are distinguishable by quantitative precipitation, complement and micro-complement fixation. Chemical modification of cow β-lactoglobulin, such as cleavage of the -His-Ile C-terminal sequence of the B variant, crystallization of the A variant with 2 moles of SDS and blocking of the -SH groups of the B variant with DTNB, do not produce molecules which are immunologically distinguishable from the parent molecule.