Bisalbuminemia associated with albumin dye binding defect

The measurement of albumin in serum and plasma

This publication was prepared at the invitation of the Analytical Methods Working Party of the Scientific Committee of the Association of Clinical Biochemists, but does not necessarily reflect the views of the Scientific Committee.

Albumin I.M.V.S.: a variant detected by a Bromcresol Green dye binding method

A unique variant of human albumin was discovered in a family following routine multiple biochemical analysis. Their sera demonstrated increased Bromcresol Green (BCG) dye binding under certain reaction conditions (excess amounts of the detergent Pegosperse in the presence of Merthiolate). This effect was also seen with a structurally similar dye, Bromcresol Purple (BCP). The variant sera also showed an altered pattern of BCG dye binding (in the presence of Merthiolate and excess Pegosperse) compared to normal sera when the temperature or the pH of the dye reagent was changed. Decreased binding of the dye 2-(4'-hydroxybenzeneazo)benzoic acid (HABA) was also noted. Similar findings were observed in six other patients over a period of 21 months. Column chromatography of the variant sera on a DEAE-Sepharose column separated the albumin into two fractions, one showing normal dye binding properties, the other showing the more extreme pattern of dye binding seen for the whole variant serum.

Comparison of methods for separating proteins using bisalbuminemia as a model

Sera from bisalbuminemic chicken-turkey hybrids contain two albumins in equal amounts. These are observed as inherited electrophoretic variants and originate from the respective chicken and turkey parents. Sera from the hybrid birds served as a model system by which fractionating and indentification procedures for evaluating serum albumin variants were compared. The two albumins in the hybrid were isolated with preparative polyacrylamide gel electrophoresis (PAGE) and starch block preparative electrophoresis. Isoelectric focusing of the hybrid albumins resulted in the isolation of the turkey albumin. Interference of ampholines prevented the complete isolation of the chicken albumin. The two albumins in the hybrid have identical molecular weights and cannot be identified by sedimentation coefficient, gel filtration behavior, or sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Because of the close relatedness the chicken and turkey albumins in the hybrid cross reacted with rabbit anti-hybrid serum as well as with rabbit anti-chicken anti-turkey sera.