Multiple Biological Functions of Novel Basic Proteins Isolated from Duck Egg White: Duck Basic Protein Small 1 (dBPS₁) and 2 (dBPS₂)

Abstract

Biological functions of duck basic protein small 1 (dBPS(1)) and 2 (dBPS(2)) were investigated by in vitro experiments. Results of agarose gel retardation assay indicated that dBPS(1) and dBPS(2) associate with RNA. Addition of NaCl or urea induced partial dissociation of dBPS(1)/dBPS(2)-RNA complex, implying that electrostatic interaction, hydrophobic interaction, and hydrogen bonds are involved in the association of dBPS(1)/dBPS(2) to RNA. dBPS(1) and dBPS(2) inhibited pancreatic lipase activity with the fifty percent inhibitory concentration (IC(50)) of 250 and 100 μg/mL, respectively. Peptic hydrolysates of dBPS(1) and those of dBPS(2) showed a potent angiotensin I-converting enzyme (ACE) inhibition with an IC(50) of 22.5 and 49.6 mg/L. The most potent ACE-inhibitory peptide was a nanopeptide (EKKGFCAGY) from dBPS(1) and an octapeptide (KYCPKVGY) from dBPS(2). These multiple biological functions of dBPS(1) and dBPS(2) may contribute to reducing the risk of lifestyle diseases.

Avian Antimicrobial Host Defense Peptides: From Biology to Therapeutic Applications

“…In fact, multiple peptides with a similar cysteine-spacing pattern have been reported earlier in the mallard duck, turkey, and black swan [46,47,48]. This group of peptides were in turn classified as ovodefensins because of their preferential expression in the oviduct with abundant presence in egg white [23].…”

Ovodefensins, an Oviduct-Specific Antimicrobial Gene Family, Have Evolved in Birds and Reptiles to Protect the Egg by Both Sequence and Intra-Six-Cysteine Sequence Motif Spacing1

“…Anas platyrhynchos OvoDA1 demonstrated good activity against E.coli DH5α (>80% reduction) yet no activity was recorded against any of the other strains used in this study. It should be noted that a study was previously carried out on duck ovodefensins which observed no antimicrobial activity [34], however this study did not report on the method used to assess activity or whether the bacterial strains used were laboratory or pathogenic. We were only able to observe activity for Anas platyrhynchos OvoDA1 (dBPS2) against the laboratory strain of E. coli are therefore the strains used in the previous study would be of interest.…”

Three-dimensional NMR Structure of Hen Egg Gallin (Chicken Ovodefensin) Reveals a New Variation of the β-Defensin Fold

“…Indeed, when used at a concentration as high as 22 M, turkey meleagrin displayed no anti-E. coli (LE392 strain) activity (32). Likewise, the duck ovodefensins dBPS1 and dBPS2 at a concentration of 56 M possess no intrinsic antimicrobial properties, at least against the following Gram-positive and negative bacteria tested: S. aureus, B. subtilis, S. enterica serovar Enteritidis, and E. coli (52). The antimicrobial spectrum of the swan ovodefensin cygnin remains still undefined.…”

“…In fact, it is likely that gallin and, to a greater extent, all ovodefensins may have biological functions other than those related to antimicrobial defense. In this regard, potent anti-lipase activities have recently been found for the duck ovodefensins dBPS1 and dBPS2, suggesting that these molecules may play a role in the protection of lipids from lipasemediated hydrolysis (52). Interestingly, dBPS1/dBPS2 proteins have been predominantly detected in the oviduct, where the synthesis of the egg takes place, and also to a lesser extent in the gall bladder, where they are believed to exert potentially their antilipase activities (33,52).…”

“…In this regard, potent anti-lipase activities have recently been found for the duck ovodefensins dBPS1 and dBPS2, suggesting that these molecules may play a role in the protection of lipids from lipasemediated hydrolysis (52). Interestingly, dBPS1/dBPS2 proteins have been predominantly detected in the oviduct, where the synthesis of the egg takes place, and also to a lesser extent in the gall bladder, where they are believed to exert potentially their antilipase activities (33,52). Similarly, maximum expression of the gallin genes is observed in the magnum (oviduct part responsible for the egg white protein synthesis) when compared with other oviduct parts (34).…”