The 1,3‐diyne linker as a rigid “i,i+7” staple for α‐helix stabilization: Stereochemistry at work

Short alphahelical peptide sequences were stabilized through Glaser‐Hay couplings of propargylated l ‐ and/or d ‐serine residues at positions i and i+7. NMR analysis confirmed a full stabilization of the helical structure when a d ‐Ser (i), l ‐Ser (i+7) combination was applied. In case two l ‐Ser residues were involved in the cyclization, the helical conformation is disrupted outside the peptide's macrocycle.     

Chromosomal sites of DNA-membrane attachment in Escherichia coli

Evidence is presented to show that both the chromosomal replication point and the chromosomal origin in Escherichia coli are associated with a structure possessing the sedimentation properties and enzyme sensitivities characteristic of membrane. The data suggest that both newly synthesized DNA strands and template DNA strands are bound at this replication point and that both strands are also bound at the origin.     

Glaser oxidative coupling on peptides: Stabilization of β-turn structure via a 1,3-butadiyne constraint

The Glaser–Eglinton reaction between either two C or N propargylglycine (Pra or NPra) amino acids, in the presence of copper(II), led to cyclic hexa- and octapeptides constrained by a butadiyne bridge. The on-resin cyclization conditions were analyzed and optimized. The consequences of this type of constraint on the three dimensional structure of these hexapeptides and octapeptides were analyzed in details by NMR and molecular dynamics. We show that stabilized short cyclic peptides could be readily prepared via the Glaser oxidative coupling either with a chiral (Pra), or achiral (NPra) residue. The 1,3-butadiyne cyclization, along with disulfide bridged and lactam cyclized hexapeptides expands the range of constrained peptides that will allow exploring the breathing of amino acids around a β-turn structure.     

Eimeria tenella: anticoccidial drug activity in cell cultures

About a decade and a half after discovery of the presence in America of the Japanese beetle, Popillia japonica Newm., Glaser and Fox came upon sick and dying beetle grubs infected with a nematode. Steiner described and named it: Neoaplectana glaseri n. sp. A method for its cultivation in vitro, the first such success for a worm parasite, was devised by Glaser (1931). This led to testing the field introduction of infective stages of the nematode for beetle grub control. Mass culture techniques in the laboratory using, for instance, nonsterile ground veal pulp, produced harvests of infective larval forms in the millions. Killing effects of the parasite were verified as well as its persistence season to season in the field.In 1940 Glaser found a way to grow N. glaseri germ-free. Its sterile culture and that of other free-living and parasitic protozoa and metazoa by Glaser and colleagues led later to axenic culture in cell-free media.