Mouse and rat beta-defensin-1 are synthesized from the 69-amino acid precursor. The mature peptide corresponds to amino acids 33-69. The sequence of this mature MBD-1 is: DQY KCL QHG GFC LRS SCP SNT KLQ GTC KPD KPN CCK S. This peptide was synthesized and disulfides were formed in their natural orientation.
Antimicrobial peptides are a common mechanism of host defense utilized by a variety of species, from insects to humans. Defensins are a large family of broad-spectrum antimicrobial peptides, identified originally in leukocytes of rabbits and humans. Defensins, cationic/polar peptides (30-35 aa; 3-4kD), are distinguished by a conserved tri-disulfides and a largely b-Sheet structure. Defensins, expressed at the cell surface, have been hypothesized to function as a biochemical barrier against microbial infection by inhibiting colonization of the epithelium by wide range of pathogenic microorganisms. In leukocytes, these peptides are stored in cytoplasmic granules and are released into phagolysosomes where they contribute to the killing of engulfed microorganisms.
The genes encoding human a and ß -defensins are clustered in a contiguous segment of chromosome 8p23. Defensins are classified into two families designated a-and ß-based on distinctive, although similar, tri-disulfide linkages in the peptides. b-defensins are slightly larger and differ in the position and arrangement of 3 disulfides. In humans, six a -defensin (cryptidins), HD 1-6 (HD1-4 are also known as HNP1-4 for Human Neutrophil Peptides), and two ß -defensins, HBD-1 and HBD-2, have been identified to date. Rat (RBD-1 and RBD-2) and mouse (MBD1-4) homologues of the human beta-defensin have also been identified.a-defensins are encoded by genes designated DEFA1-6, whereas human b-defensins are encoded by the DEFB1 and DEFb2 genes.
Storage and Stability:Store lyophilized powder at -20°C. Product may be reconstituted prior to use using sterile PBS; aliquots can be stored -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
