Synthesis and sst(2) binding profiles of new [Tyr(3)]octreotate analogs.

One of the main objectives of our current work is the development of new somatostatin analogs that would retain the general characteristics of [Tyr(3)]octreotate (Tate) while showing potential for clinical application. In this respect, study of their interaction with the sst(2) is crucial in providing preliminary structure-activity relationships data. In the present work we report on the synthesis and the preliminary biological evaluation of a total of 15 new structurally modified [Tyr(3)]octreotate analogs. The binding affinities were determined during competition binding assays in sst(2)-positive rat acinar pancreatic AR4-2J cell membranes using [(125)I-Tyr(3)]octreotide as the radioligand.     

Long-term satellite tracking of white stork ( Ciconia ciconia) migration: constancy versus variability

During satellite-tracking investigations of 140 white storks (Ciconia ciconia), one individual, the long-term world record holder among birds, was followed along 12 migratory journeys over a period of 10 years. This long-term study confirms what previous several-year tracking studies of white storks had indicated: there can be great variability from year to year in the choice of winter quarters as well as in the routes and times of migration, intermediate destinations and stop-over periods, but constancy of winter quarters and migration routes is also possible. The variability may well be caused by external factors, of which food supply is probably predominant.Communicated by F. Bairlein     

Fungal ferritins: The ferritin from mycelia of Absidia spinosa is a bacterioferritin

Two distinct ferritin like iron containing proteins have been identified and isolated from the fungus Absidia spinosa; one from the spores and another from the mycelia. The mycelial protein has been purified and consists of two subunits of approx. 20 kDa. The N-terminal sequences of both subunits have been determined. The holoprotein as isolated contains approx. 750 iron atoms/molecule and exhibits a heme-like UV-Vis spectrum. Based on the heme spectrum and the high degree of sequence homology found, it has been established that the mycelial protein is a bacterioferritin. This is the first example demonstrating the presence of a bacterioferritin in a eukaryotic organism.