Red microalgae genera Porphyridium are photoautotrophic with potential application as a natural source of high-value chemicals, including sulfated exopolysaccharides (EPs), phycobiliproteins (PBPs), and long-chain polyunsaturated fatty acids (LC-PUFAs) such α-linolenic (ALA), arachidonic (ARA), eicosapentaenoic acid (EPA). Their good tolerances toward dynamic environmental changes lead them to ...

One group of penicillin target enzymes, the class A high-molecular-weight penicillin-binding proteins (PBPs), are bimodular enzymes. In addition to a central penicillin-binding-transpeptidase domain, they contain an N-terminal putative glycosyltransferase domain. Mutations in the genes for each of the three Streptococcus pneumoniae class A PBPs, PBP1a, PBP1b, and PBP2a, were isolated by inserti...

The pheromone-binding proteins (PBPs), which exist at a high concentration in the sensillum lymph surrounding olfactory neurons, are proposed to be important in pheromone detection and discrimination in insects. Here, we present a systematic study of PBP-ligand interaction kinetics. We find that PBP2, from the gypsy moth, Lymantria dispar, associates and dissociates slowly with its biofunctiona...

The pH-conditional morphology mutant of Klebsiella pneumoniae strain MirM7 grows as cocci at pH 7 and as rods at pH 5.8. The mutant has a high-level mecillinam resistance (50% lethal dose greater than 200 micrograms/ml) in both forms. When broth cultures of the rod-shaped mutant were grown with 0.7 microgram of mecillinam per ml, cells assumed a round shape and continued to divided at a higher ...

The enormous capacity of the male silkmoth Bombyx mori in recognizing and discriminating bombykol and bombykal is based on distinct sensory neurons in the antennal sensilla hairs. The hydrophobic pheromonal compounds are supposed to be ferried by soluble pheromone-binding proteins (PBPs) through the sensillum lymph toward the receptors in the dendritic membrane. We have generated stable cell li...

The penicillin-resistant Enterococcus hirae R40 has a typical profile of membrane-bound penicillin-binding proteins (PBPs) except that the 71 kDa PBP5 of low penicillin affinity represents about 50% of all the PBPs present. Water-soluble tryptic-digest peptides were selectively produced from PBP5, their N-terminal regions were sequenced and synthetic oligonucleotides were used as primers to gen...

We investigated the binding affinities of SM-7338 for penicillin-binding proteins (PBPs) and the morphological changes induced by it compared with those of imipenem. Both SM-7338 and imipenem had the highest binding affinities for PBP-2 of Escherichia coli, which were in good agreement with the primary morphological response of spherical cell formation. SM-7338 also showed high affinities for P...

Penicillin-resistant isolates of Streptococcus pneumoniae generally contain mosaic genes encoding the low-affinity penicillin-binding proteins (PBPs) PBP2x, PBP2b, and PBP1a. We now present evidence that PBP2a and PBP1b also appear to be low-affinity variants and are encoded by distinct alleles in beta-lactam-resistant transformants of S. pneumoniae obtained with chromosomal donor DNA from a St...

Compared with most penicillin-susceptible isolates of Streptococcus pneumoniae, penicillin-resistant clinical isolate Hun 663 contains mosaic penicillin-binding protein (PBP) genes encoding PBPs with reduced penicillin affinities, anomalous molecular sizes, and also cell walls of unusual chemical composition. Chromosomal DNA prepared from Hun 663 was used to transform susceptible recipient cell...

Newly synthesized 5-acylaminothiazolium salts and one 5-acylaminothiazolidine, considering their chemical structure and reactivity, have been proposed as potential inhibitors of bacterial serine DD-peptidases. A moderate antibiotic activity with (5-phenylacetylamino-3-thiazolio)acetate and (5-phenylacetylaminothiazolidin-3-yl)acetic acid was observed on Staphylococcus aureus ATCC 25923. The met...