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B Kühlmorgen

Publications and source records attributed to B Kühlmorgen.

6 recordsLinked to original sources
PubMed1995

Tetrabrachion: a filamentous archaebacterial surface protein assembly of unusual structure and extreme stability.

The surface (S-) layer of the hyperthermophilic archaebacterium Staphylothermus marinus was isolated, dissected into separate domains by chemical and proteolytic methods, and analyzed by spectroscopic, electron microscopic and biochemical techniques. The S-layer is formed by a poorly ordered meshwork of branched, filiform morphological subunits resembling dandelion seed-heads. A morphological subunit (christened by us tetrabrachion) consists of a 70 nm long, almost perfectly straight stalk ending in four straight arms of 24 nm length that provide lateral connectivity by end-to-end contacts. At 32 nm from the branching point, tetrabrachion carries two globular particles of 10 nm diameter that have both tryptic and chymotryptic protease activity. Tetrabrachion is built by a tetramer of M(r) 92,000 polypeptides that form a parallel, four-stranded alpha-helical rod and separate at one end into four strands. These strands interact in a 1:1 stoichiometry with polypeptides of M(r) 85,000 to form the arms. The arms are composed entirely of beta-sheets. All S-layer components contain bound carbohydrates (glucose, mannose, and glucosamine) at a ratio of 38 g/100 g protein for the complete tetrabrachion-protease complex. The unique structure of tetrabrachion is reflected in an extreme thermal stability in the presence of strong denaturants (1% (w/v) SDS of 6M guanidine): the arms, which are stabilized by intramolecular disulphide bridges, melt around 115 degrees C under non-reducing conditions, whereas the stalk sustains heating up to about 130 degrees C. Complete denaturation of the stalk domain requires treatment with 70% (v/v) sulfuric acid or with fuming trifluoromethanesulfonic acid. The globular protease can be heated to 90 degrees C in 6M guanidine and to 120 degrees C in 1% SDS and represents one of the most stable proteases characterized to date.

Archaea↗
PubMed1975

An approach to the interpretation of the communicative meaning of visual signals in agonistic behavior of squirrel monkeys.

The repertoire of the visually recognizable agonistice signals of the squirrel monkey can be divided up into classes in such a manner that elements of the same class have a similar, and elements of different classes a different communicative meaning. The differences between these classes are described using quantitative values. An attempt is made to derive clues from these differences for an interpretation of the communicative meaning of the individual classes. The admissibility of the criteria used and the question of the general validity of the quantitative values are discussed.

Aggression↗