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RESEARCH PRODUCT

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Developing an artificial oxygen carrier for use in humans, we polymerize native haemoglobin and myoglobin, using bifunctional, amino group specific cross-linkers, to soluble, so-called hyperpolymers. These polymers, like other polymerized globular proteins, are members of a new class of macromolecues which consist of macromolecular base units. They all have, due to the mechanisms of the chemical reaction, broad distributions of molecular weights. Fractions of hyperpolymers of human haemoglobin were obtained by employing preparative gel-permeation (size-exclusion) chromatography. The calibration curve of analytical gel-permeation chromatography (GPC) for haemoglobin hyperpolymers was determined using mean molecular weights of some fractions, as assessed by osmometric and light scattering measurements. In analogy to native globular proteins, the calibration curve for haemoglobin polymers — within the range of molecular weights considered here, and within the experimental accuracy — is a straight line. All fractions of haemoglobin polymers were further characterized with the aid of calibrated analytical GPC. Mean non-uniformity was about, 0,6. The dependence of the logarithm of the intrinsic viscosity [η] on the logarithm of the viscosity-average molecular weight Mη 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 haemoglobin 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-solution diagram”, and a characteristic calibration curve in GPC. The special structure-in-solution of the polymer proteins is a novel molecular superstructure. The intrinsic viscosity for native myoglobin was found to be 3,5 mL/g.