@article{KruseLehrnbecherSebald1991, author = {Kruse, N. and Lehrnbecher, T. and Sebald, Walter}, title = {Site-directed mutagenesis reveals the importance of disulfide bridges and aromatic residues for structure and proliferative activity of human interleukin-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62505}, year = {1991}, abstract = {Mutant proteins (muteins) of human lnterleukin-4 (llA) were constructed by means of in vitro mutagenesis. The muteins were expressed in E. co/1, submitted to a renaturation and purification protocol and analysed for biological activity. Exchange of the cysteines at either position 46 or 99 which form one of the three disulfide bridges resulted. in a nearly co•mplete loss · of biological actiyity and an unstable protein. The exchange of tyrosine 124 also inactivated the protein, while a mutation of tyrosine 56 left some residual activity. Exchange of the other four cysteines or of · the single tryptophane had smaller etTects.}, subject = {Biochemie}, language = {en} } @article{MerzFliednerOrschescheketal.1991, author = {Merz, H. and Fliedner, A. and Orscheschek, K. and Binder, T. and Sebald, Walter and M{\"u}ller-Hermelink, H. K. and Feller, A. C.}, title = {Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62483}, year = {1991}, abstract = {No abstract available}, subject = {Biochemie}, language = {en} } @article{LehrnbecherMerzSebaldetal.1991, author = {Lehrnbecher, T. and Merz, H. and Sebald, Walter and Poot, M.}, title = {Interleukin 4 drives phytohemagglutinin-activated T cells through several cell cycles: no synergism between interleukin 2 and interleukin 4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-62491}, year = {1991}, abstract = {Cell kinetic studies of T cells stimulated with the interleukin 2 (11-2), D-4, or both lymphokines were performed with conventional [3H] thymidine incorporation and with the bivariate BrdU/Hoechst technique. 11-2 and 11-4 are able to drive phytohemagglutininactivated T cells through more than one cell cycle. Neither synergistic nor inhibitory efl'ect on T -cell proliferationwas seen for the stimulation with both 11-2 and 11-4 as compared with the effect ofll-2 alone. The quantitative data ofthe cell cycle distribution ofphytohemagglutininactivated T cells suggestthat the population ofll-4-responsive cells is at least an overlapping population, if not a real subset of the ·population of the 11-2-responsive cells.}, subject = {Biochemie}, language = {en} }