A voltage-gated ion channel model inferred from the crystal structure of alamethicin at 1.5-A resolution

The crystal structure of alamethicin in nonaqueous solvent has been determined, and refined at 1.5-A resolution. The molecular conformation of the three crystallographically independent molecules is largely alpha-helical with a bend in the helix axis at an internal proline residue. The helix structure is highly amphipathic as most of the solvent-accessible polar atoms lie on a narrow strip of surface parallel to the helix axis. Molecular models for the voltage-gated ion channel, with n-fold symmetry and based on the molecular conformations observed in the crystal, are characterized by strong surface complementarity, a hydrophilic interior and a hydrophobic exterior. The channel structures are stabilized by a hydrated annulus of hydrogen-bonded glutamine residues which produce the greatest restriction in the channel diameter.     

A glycoprotein: galactosyltransferase activity in the ascitic fluid and serum of mice with the YC8 tumor]

Tranfer of (14C)-gal from exogenous UDP(14C)-gal has been demonstrated with ovomucoid as glycoprotein acceptor in ascitic fluid sera from Balb/c mice bearing isogenic YC8 tumor. Transfer exists without ovomucoid, in great ratio in ascitic fluid and in sera from ascitic mice too, showing occurrence of endogenous acceptors, the origin of which has to be proved.     

The protective effect of small amounts of selenite in sublimate intoxication

Résumé L'injection de très petites quantités de sélénite de sodium, administrées simultanément ou 1 h après l'intoxication par le sublimé corrosif, en abaisse considérablement la toxicité: les rats blancs intoxiqués par une dose létale de sublime corrosif survivent sous l'effet du sélénite dans un % important et les lésions typiques des reins et d'autres organes n'apparaissent pas.     

Wirkung des Mondlichtes auf die Nachtaktivität von Zugvögeln. — Lotsenversuch an Rotkehlchen (Erithacus rubecula) und Gartenrotschwänzen (Phoenicurus phoenicurus)

Summary 8 Robins (Erithacus rubecula) and 3 Redstarts (Phoenicurus phoenicurus) were maintained in registration cages in autumn 1965. Locomotor activity was registered continuously under natural light conditions, temperature remaining fairly constant. All but one bird developed nocturnal restlessness (Zugunruhe) at least during the migratory season (Figure 1). 8 out of 10 birds showed a higher mean activity at night during full moon phases than during new moon phases; 2 birds showed roughly equal activity during both phases of the cycle (Figure 2). Since the measurements of nocturnal activity at least partially correspond to migratory motivation, it is reasonable to assume that free-living individuals of the species investigated are more active during nights in the full moon phase and possibly fly farther than at dark nights.     

Cytologie fine des cellules interstitielles du testicule du poissonLebistes reticulatus R.

Summary The active interstitial cells of the testis ofLebistes reticulatus R. have numerous, big, dense mitochondria of tubular structure and a developed endoplasmic reticulum. The formation of lipochrome pigment granules corresponds to a degenerative evolution of these cells.