On page 892 of the December 1965 issue of Blood (Vol. XXVI, No. 6), P. Lauf was unintentionally omitted as co-author of Abstract #52 presented at the Eighth Annual Meeting of the American Society of Hematology. The complete abstract is reprinted below.
HETEROGENEITY OF WATER-SOLUBLE PROTEIN COMPONENTS OF THE RED CELL MEMBRANE. M. D. Poulik and P. Lauf (Introduced by W. W. Zuelzer°), Child Research Center of Michigan, Detroit, Mich.
Separation and isolation of the structural components of the red cell stroma was undertaken. Hemoglobin-free stroma (1-3 per cent hemoglobin per dry weight) of the major blood groups was prepared and water-soluble protein was extracted with nbutanol-water at -2 C. The yield was increased by reductive cleavage of the stroma prior to extraction. A, B, M and N blood group activity was demonstrated by hemagglutination inhibition technic in the water-soluble material. The Rho (D)-activity was destroyed by reductive cleavage or by butanol extraction alone. The water-soluble material was subjected to chromatography on Sephadex G-200, and 2 well-defined peaks were separated. Ultraviolet spectra of the starting material and those obtained with the 2 peaks showed that a separation of a lipid-like material was affected. Peak A contained most of the protein and was immunologically active. This chromatographically homogeneous material of peak A was found to be heterogeneous by starch gel electrophoresis conducted in the presence of urea and mercaptoethanol. The effect of several lipid solvents on the electrophoretic patterns was also investigated. A highly negative-charged subcomponent was separated from all the major blood groups. Chemical and immunologic data will be discussed.