The CD28/B7 system provides costimulatory signals necessary for optimal T cell activation. We have examined the effects of blocking B7.1 and/or B7.2 in an in vitro system using TCR transgenic T cells specific for myelin basic protein. Activation of naive T cells was found to be B7.2 dependent and not dependent on the presence of B7.1 molecules. However, increasing the strength of signal through...

Peptoids (oligo N-substituted glycines) are peptide analogues, which can be designed to mimic host antimicrobial peptides, with the advantage that they resistant proteolytic degradation. Few studies on efficacy of peptoids have focused Gram negative anaerobic microbes associated clinical infections, commonly recalcitrant antibiotic treatment. We therefore studied cytotoxicity and antibiofilm ac...

Oral delivery of peptide and protein drugs has potential advantages for the aquaculture industry. The bioavailability of proteins and peptides from the intestinal tract is very low. This can be attributed in part to the proteolytic activities of the intestine. Bovine serum albumin (BSA), human (hLHRH) and salmon (sLHRH) luteinizing-hormone releasing hormones were used to evaluate the proteolyti...

A series of thapsigargin (TG) analogues, containing an amino acid applicable for conjugation to a peptide specifically cleaved by prostate-specific antigen (PSA), has been prepared to develop the drug-moiety of prodrugs for treatment of prostatic cancer. The analogues were synthesized by converting TG into O-8-debutanoylthapsigargin (DBTG) and esterifying O-8 of DBTG with various amino acid lin...

BACKGROUND Cyclotides are useful scaffolds to stabilize bioactive peptides. RESULTS Four melanocortin analogues of kalata B1 were synthesized. One is a selective MC4R agonist. CONCLUSION The analogues retain the native kalata B1 scaffold and introduce a designed pharmacological activity, validating cyclotides as protein engineering scaffolds. SIGNIFICANCE A novel type of melanocortin agon...

The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine re...

Even several decades after pioneer publications there is continued interest in the construction and synthesis of a variety of novel oligonucleotide analogues. The first oligonucleotide analogues which had a regular, predetermined structure containing nucleoside units joined with carbonate, carbamate, hydroxyacetate and hydroxyacetamide tethers have been developed in the 1970s. Further progress ...

The marine environment has been poorly explored in terms of potential new molecules possessing antibacterial activity. Antimicrobial peptides (AMPs) offer a new potential class of pharmaceuticals; however, further optimization is needed if AMPs are to find broad use as antibiotics. We focused our studies on a peptide derived from the epidermal mucus of hagfish (Myxine glutinosa L.), which was p...

HP (2-20), a 19-residue peptide derived from the N-terminus of Helicobacter pylori ribosomal protein L1, has antimicrobial activity but is not cytotoxic to human erythrocytes. We synthesized several peptide analogues to investigate the effects of substitutions on structure and antimicrobial activity. Replacement of Gln16 and Asp18 with tryptophan [anal-3 (analogue-3)] caused a dramatic increase...