Total synthesis of the antibiotic polymyxin B1

Zusammenfassung Es wird über die Synthese des cyclo-Decapeptides 7, in welchem alle Dab-Reste diel-Konfiguration aufweisen, berichtet. Dieses erwies sich als identisch mit natürlichem Polymyxin B₁ (Figur 2).     

Protein constituents of the eggshell: eggshell-specific matrix proteins

In this article, we review the results of recent proteomic and genomic analyses of eggshell matrix proteins and draw attention to the impact of these data on current understanding of eggshell formation and function. Eggshell-specific matrix proteins from avian (ovocleidins and ovocalyxins) and non-avian (paleovaterin) shells are discussed. Two possible roles for eggshell-specific matrix proteins have been proposed; both reflect the protective function of the eggshell in avian reproduction: regulation of eggshell mineralization and antimicrobial defense. An emerging concept is the dual role (mineralization/antimicrobial protection) that certain eggshell matrix proteins can play.     

Volatile constituents of the scent gland reservoir ofAspavia acuminata

Summary Volatile components of the scent gland complex of the adult bug ofAspavia acuminata, an agricultural pest from Nigeria, have been identified by the technique of combined gas chromatograph-mass spectrometry. Of specific interest is the presence in the gland reservoir of hex-2-enal, 4-oxo-hex-2-enal and 4-oxo-oct-2-enal.The author is grateful to the Bayero University Research and Higher Degrees Committee for financial support, Dr B. W. Staddon for his valuable assistance, Dr D. E. Games for arranging mass spectral facilities.     

Differential thermal analysis of the organic fraction of bone]

Thermal decomposition analysis of Bovine femur bone has been carried out by means of a Micro Differential Thermal Analyser. The analysis of both thermograms and amino acid compositions has revealed the complexity of collagen degradation mechanisms.     

Determination of the structure of the peptide moiety of the antibiotic albomycin

Zusammenfassung Der Peptidteil des Antibioticums Albomycin wurde aufgeklärt durch Überführung der -Hydroxy-ornithinreste in Glutaminsäurereste und anschliessende saure Partialhydrolyse, wobei sechs Peptide resultierten, deren Kombination eine eindeutige Strukturformel lieferten.     

N-cadherin detected in the membrane fraction of lens fiber cells

Summary N-cadherin was identified as a glycoprotein present in the fiber cell membranes of frog, chick, bovine, rabbit and human lenses. The molecular size of N-cadherin varies with the species. Homogenization of the chick lens in the presence of Ca²⁺ resulted in a decrease in the concentration of N-cadherin. This suggests that the lens contains a Ca²⁺-activated protease which can act on N-cadherin.     

N-cadherin detected in the membrane fraction of lens fiber cells

N-cadherin was identified as a glycoprotein present in the fiber cell membranes of frog, chick, bovine, rabbit and human lenses. The molecular size of N-cadherin varies with the species. Homogenization of the chick lens in the presence of Ca2+ resulted in a decrease in the concentration of N-cadherin. This suggests that the lens contains a Ca2(+)-activated protease which can act on N-cadherin.