Peptides as ligands for immunoadsorption exhibit several potential advantages over native proteins. Two newly developed adsorbers are based on peptides covalently coupled to sepharose CL-4B. Globaffin is capable of binding immunoglobulins independent from their antigen specificity and thus, applicable in transplant recipients and several antibody mediated autoimmune diseases. Among others, the most important disorders suitable for the treatment with Globaffin are rheumatoid arthritis, systemic lupus erythematosus, and acute renal transplant rejection. Coraffin is a specific adsorber using two linear peptide ligands mimicking epitopes of the beta1-adrenergic receptor, that bind corresponding autoantibodies from patients suffering from idiopathic dilated cardiomyopathy. Specific immunoadsorption has been shown to be beneficial for patients with dilated cardiomyopathy. Coraffin can be used as a new therapeutic option for these patients, who get only limited benefit from medical therapy. Both adsorbers may be combined with all approved apheresis control devices available.

Monomeric and trimeric PS I complexes missing the three stromal subunits E,C and D (termed PS I core complexes) were prepared from the thermophilic cyanobacterium Synechococcus sp. by incubation with urea. The subunits E,C and D are sequentially removed. In the monomeric PS I the subunit C is removed with a half life of approx. 5 min. This is about eight times faster than in the trimeric PS I complex. In parallel with the removal of the FAB containing subunit C the reduction kinetics of P700+ changed from a half life of about 25 ms to about 750 μs. The partner of P700+ in the 750 μs charge recombination was identified to be FX by the difference spectrum of this phase. There are some minor differences in the spectra of trimeric and monomeric PS I core complexes. At 77K the forward electron transfer from A − 1 to FX is blocked in the major fraction of the PS I core complexes and P700+A− 1 recombines with a half life of about 220 μs. In the remaining fraction P700+FX − is formed and decays with a half life of approx. 10 ms at 77 K. The kinetics of the forward electron transfer from A− 1 to the iron‐sulfur‐clusters was measured in the native PS I and the corresponding core complexes. The reoxidation kinetics of A− 1 are identical in both cases (t 12 = 180 ns). We conclude that Fx is an obligatory intermediate in the normal forward electron transfer.

Bacteriophage SPP1 portal protein is a large cyclical homo-oligomer composed of 13 subunits. The solution structure and assembly behavior of this protein with high-point rotational symmetry was characterized. The purified protein was present as a monodisperse population of 13-mers, named gp6 H , at univalent salt concentrations in the hundred millimolar range ($ 250 mm NaCl) or in the presence of bivalent cations in the millimolar range ($ 5 mm MgCl 2 ). Gp6 H had a slightly higher sedimentation coefficient, a smaller shapedependent frictional ratio, and a higher rate of intersubunit cross-linking in the presence of magnesium than in its absence. In the absence of bivalent cations and at univalent salt concentrations below 250 mm, the 13-mer molecules dissociated partially into stable monomers, named gp6 L . The monomer had a somewhat different shape from the subunit present in the 13-mer, but maintained a defined tertiary structure. The association±dissociation equilibrium was mainly between the monomer and the 13-mer with a minor population of intermediate oligomers. Their interconversion was strongly influenced by the ionic environment. Under physiological conditions, the concentration of Mg 2+ found in the Bacillus subtilis cytoplasm (10±50 mm) probably promotes complete association of gp6 into 13-mer rings with a compact conformation.

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