Abstract: Biologically active protein compositions comprising protein or a protein substrate bound onto a polyamide of the general formula: ##STR1## in which R and R.sub.1, which may be the same or different, are polyamide residues bound onto the amido group,R.sub.2 is the residue of a compound which can be condensed with formaldehyde and which contains at least one further reactive group,R.sub.3 is the residue of a bi- or poly-functional protein reagent,n is 0 or 1, andP is a biologically active protein;these compositions are obtainable by the reaction of a polyamides with amounts, equimolar to one another, of formaldehyde and of a compound condensable with formaldehyde, in a solvent for polyamides, reacting the product thereby obtained with a bi- or poly-functional protein reagent and coupling the resulting reaction product with the biologically active protein or protein substrate.

Abstract: A new enzyme, cholesteroloxidase, is prepared by recovering same from microorganisms, preferably by washing a cholesterol-converting microorganism with butanol/water, disintegrating the microorganism culture and extracting same with a buffer solution containing a non-ionic surface-active agent, and isolating cholesterol oxidase from the extract.

Abstract: Carrier-bound macromolecular compounds, especially bioactive macromolecular compounds, are produced by reacting a macromolecular compound A with a coupling compound B containing at least one reactive function capable of coupling with compound A and at least one further reactive function capable of polymerization, adding to the resulting coupled reaction product AB an unswollen molecular sieve material having cross-linking sufficient to exclude penetration by compound A, and polymerizing the polymerizable group of the coupled product AB in the molecular sieve material to form a polymer body in the molecular sieve material and fix compound A on the surface of the molecular sieve material. Compound A can be, e.g., an enzyme, antibody or hormone, and coupling compound B typically contains, as the coupable function, an alkylation or acylation group such as oxirane, ethyleneimine, halide, acid halide, azide or anhydride groups, and, as the polymerizable function, a carbon-carbon or carbon-oxygen double bond.

Abstract: Biologically active proteins are bound onto an insoluble carrier by reacting such protein in an aqueous phase with a carrier comprising an activated polysaccharide having a hydrophilic graft co-polmyer grafted thereinto.

Abstract: Carrier-bound proteins are prepared by reacting a protein in aqueous solution with a coupling compound having at least one group capable of acylating or alkylating proteins and at least one additional group capable of producing a bond with a carrier material, and reacting the resulting product with a carrier material, optionally forming the carrier material in situ by polymerization of a monomer or monomer mixture in the presence of said product.