[1] UNIV TUBINGEN,INST PHYSIOL CHEM,D-7400 TUBINGEN 1,FED REP GER
[2] UNIV TUBINGEN,INST MIKROBIOL 2,D-7400 TUBINGEN 1,FED REP GER
[3] UNIV ULM,INST TRANSFUS WESEN,D-7900 ULM,FED REP GER
[4] CIBA GEIGY AG,INST BIOTECHNOL,CH-4002 BASEL,SWITZERLAND
[5] HEBREW UNIV JERUSALEM,JERUSALEM,ISRAEL