CROSS-LINKED GLOBULAR-PROTEINS - A NEW CL ASS OF SEMISYNTHETIC MACROMOLECULES - CHARACTERIZATION OF THEIR STRUCTURE IN SOLUTION FOR HYPERPOLYMERIC HEMOGLOBIN AND MYOGLOBIN BY MEANS OF SIZE-EXCLUSION CHROMATOGRAPHY, VISCOSIMETRY, OSMOMETRY AND LIGHT-SCATTERING

Developing an artificial oxygen carrier for use in humans, we polymeri ze native haemoglobin and myoglobin, using bifunctional, amino group s pecific cross-linkers, to soluble, so-called hyperpolymers. These poly mers, like other polymerized globular proteins, are members of a new c lass of macromolecues which consist of macromolecular base units. They all have, due to the mechanisms of the chemical reaction, broad distr ibutions of molecular weights. Fractions of hyperpolymers of human hae moglobin were obtained by employing preparative gel-permeation (size-e xclusion) chromatography. The calibration curve of analytical gel-perm eation chromatography (GPC) for haemoglobin hyperpolymers was determin ed using mean molecular weights of some fractions, as assessed by osmo metric and light scattering measurements. In analogy to native globula r proteins, the calibration curve for haemoglobin polymers - within th e range of molecular weights considered here, and within the experimen tal accuracy - is a straight line. All fractions of haemoglobin polyme rs were further characterized with the aid of calibrated analytical GP C. Mean nonuniformity was about 0,6. The dependence of the logarithm o f the intrinsic viscosity [eta] on the logarithm of the viscosity-aver age molecular weight (M) over bar(eta) of the fractions (the curve in the ''structure-in-solution diagram'') also is a straight line, which is true for haemoglobin and for myoglobin polymers as well. Its first derivative is the exponent a of the Mark-Houwink function; for haemogl obin and myoglobin polymers the values are 0,39 and 0,46, respectively . Haemoglobin and myoglobin hyperpolymers, as members of the new class of polymers, both have a characteristic so-called ''structure-in-solu tion diagram'', and a characteristic calibration curve in GPC. The spe cial structure-in-solution of the polymer proteins is a novel molecula r superstructure. The intrinsic viscosity for native myoglobin was fou nd to be 3,5 mL/g.