-
[show abstract]
[hide abstract]
ABSTRACT: Five novel antimicrobial peptides (temporin-LK1, rugosin-LK1, rugosin-LK2, gaegurin-LK1, and gaegurin-LK2) are purified and characterized from Kuhl's wart frog skin secretions, Limnonectes kuhlii. They share obvious similarity to temporin, rugosin, and gaegurin antimicrobial peptide family, respectively. Their amino acid sequences were determined by Edman degradation and mass spectrometry, and further confirmed by cDNA cloning. Nine cDNA sequences encoding precursors of these five purified antimicrobial peptides and other four hypothetical antimicrobial peptides were cloned from the skin cDNA library of L. kuhlii. The deduced precursors are composed of a predicted signal peptide, an acidic spacer peptide, and a mature antimicrobial peptide. Most of them showed strong antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi. The current work identified and characterized three families of antimicrobial peptides from L. kuhlii skins and confirmed that the genus of Limnonectes amphibians share similar antimicrobial peptide families with the genus of Rana amphibians. In addition, a unique antimicrobial peptide (temporin-LK1) with 17 residues including four phenylalanines, which is significantly different from other temporins (16 residues, one or two phenylalanines), was identified in this work. Such unique structure might provide novel template or leading structure to design antimicrobial agents.
Molecular Biology Reports 10/2012; · 2.93 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The insect of Eupolyphaga sinensis Walker has been used as traditional anti-thrombosis medicine without bleeding risk for several hundreds years in eastern countries. Our previous work has identified a bi-functional anti-thrombosis protein containing both direct-acting fibrin(ogen)olytic and plasminogen-activating activities from the insect. By proteomics and transcriptome analysis, 105 serine proteases belonging to four families were identified from the ground beetle, E. sinensis and the classification is for serine proteases of this organism. Pharmacological test indicated that 5 (eupolytin 1-5) of them have the abilities to hydrolyze fibrin(ogen) and/or activate plasminogen. The current work revealed the extreme diversity of anti-thrombosis components in E. sinensis and anti-thrombosis molecular mechanisms of the traditional medicinal insect, and provided many templates for the development of new thrombolytic agents. Especially, these proteins, which contain both plasmin- and PA (plasminogen-activating)-like activities, are excellent candidates for anti-thrombosis medicines.
Insect biochemistry and molecular biology 08/2012; 42(8):537-44. · 3.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Direct-acting fibrin(ogen)olytic agents such as plasmin have been proved to contain effective and safety thrombolytic potential. Unfortunately, plasmin is ineffective when administered by the intravenous route because it was neutralized by plasma antiplasmin. Direct-acting fibrin(ogen)olytic agents with resistance against antiplasmin will brighten the prospect of anti-thrombosis. As reported in 'Compendium of Materia Medica', the insect of Eupolyphaga sinensis Walker has been used as traditional anti-thrombosis medicine without bleeding risk for several hundreds years. Currently, we have identified a fibrin(ogen)olytic protein (Eupolytin1) containing both fibrin(ogen)olytic and plasminogen-activating (PA) activities from the beetle, E. sinensis.
To investigate the role of native and recombinant eupolytin1 in fibrin(ogen)olytic and plasminogen-activating processes.
Using thrombus animal model, eupolytin1 was proved to contain strong and rapid thrombolytic ability and safety in vivo, which are better than that of urokinase. Most importantly, no bleeding complications were appeared even the intravenous dose up to 0.12 µmol/kg body weight (3 times of tested dose which could completely lyse experimental thrombi) in rabbits. It is the first report of thrombolytic agents containing both direct-acting fibrin(ogen)olytic and plasminogen-activating activities.
The study identified novel thrombolytic agent with prospecting clinical potential because of its bi-functional merits containing both plasmin- and PA-like activities and unique pharmacological kinetics in vivo.
PLoS ONE 01/2011; 6(3):e17519. · 4.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: While investigating antimicrobial peptide diversity of Amolops loloensis, five novel antimicrobial peptides belonging to two families were identified from skin secretions of this frog. The first family including two members is esculentin-2-AL (esculentin-2-ALa and -ALb); the second family including three members is temporin-AL (temporin-ALd to -ALf). The family of esculentin-2-AL is composed of 37 amino acid residues (aa); the family of temporin-AL is composed of 16, 13 and 10 aa, respectively. All of these antimicrobial peptides showed antimicrobial activities against tested microorganisms. cDNAs encoding precursors of esculentin-2-ALs and temporin-ALs were cloned from the skin cDNA library of A. loloensis. All the precursors share similar overall structures. There is a typical prohormone processing signal (Lys-Arg) located between the acidic propiece and the mature peptide. The antimicrobial peptide family of esculentin-2 is firstly reported in the genus of Amolops. Combined with previous reports, a total of four antimicrobial peptide families have been identified from the genus of Amolops; three of them are also found in the genus of Rana. These results suggest the possible evolutionary connection between the genera Amolops and Rana.
Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology 10/2009; 155(1):72-6. · 1.61 Impact Factor
