Biosynthesis and antimicrobial evaluation of backbone-cyclized α-defensins.

Defensins are antimicrobial peptides that are important in the innate immune defense of mammals. Upon stimulation by bacterial antigens, enteric α-defensins are secreted into the intestinal lumen where they have potent microbicidal activities. Cryptdin-4 (Crp4) is an α-defensin expressed in Paneth cells of the mouse small intestine and the most bactericidal of the known cryptdin isoforms.

Increased hydrophobicity and decreased backbone flexibility explain the lower solubility of a cataract-linked mutant of γD-crystallin.

A number of point mutations in γD-crystallin are associated with human cataract. The Pro23-to-Thr (P23T) mutation is perhaps the most common, is geographically widespread, and presents itself in a variety of phenotypes. It is therefore important to understand the molecular basis of lens opacity due to this mutation.

Palmitic Acid Is a Novel CD4 Fusion Inhibitor That Blocks HIV Entry and Infection.

The high rate of HIV-1 mutation and the frequent sexual transmission highlight the need for novel therapeutic modalities with broad activity against both CXCR4 (X4) and CCR5 (R5)-tropic viruses. We investigated a large number of natural products, and from Sargassum fusiforme we isolated and identified palmitic acid (PA) as a natural small bioactive molecule with activity against HIV-1 infection. Treatment with 100 microM PA inhibited both X4 and R5 independent infection in the T cell line up to 70%.

NMR study of the cataract-linked P23T mutant of human gammaD-crystallin shows minor changes in hydrophobic patches that reflect its retrograde solubility.

The Pro23 to Thr (P23T) mutation in human gammaD-crystallin (HGD) shows several cataract phenotypes. We found earlier [A. Pande, O.

Role of the interdomain linker in distance determination for remote cleavage by homing endonuclease I-TevI.

I-TevI is a modular intron-encoded endonuclease, consisting of an N-terminal catalytic domain and a C-terminal DNA-binding domain, joined by a 75 amino acid linker. This linker can be divided into three regions, starting at the N terminus: the deletion-intolerant (DI) region; the deletion-tolerant (DT) region; and a zinc finger, which acts as a distance determinant for cleavage. To further explore linker function, we generated deletion and substitution mutants that were tested for their preference to cleave at a particular distance or at the correct sequence.