Inhibition of the function of activated properdin by squid chondroitin sulfate E glycosaminoglycan and murine bone marrow-derived mast cell chondroitin sulfate E proteoglycan

We compared the relative capacities of two over-sulfated glycosaminoglycans, heparin and chondroitin sulfate E, to alter the function of native properdin (nP) and activated properdin (aP) in the formation and stabilization of the amplification C3 convertase (C3b,Bb). Heparin was more active on a weight basis than chondroitin sulfate E in inhibiting the formation of C3b,Bb without or with nP, but had no influence on the decay of a pre-formed convertase, either unstabilized or stabilized with nP or aP. In contrast, chondroitin sulfate E was over 10-fold more active than heparin in preventing the formation of C3b,Bb in the presence of aP, and gave dose-related acceleration of decay of pre-formed C3b,Bb,aP but not of unstabilized or nP-stabilized pre-formed convertase. The inhibitory effect of both glycosaminoglycans on the formation of C3b,Bb in the presence of nP or aP was less when the number of C3b sites per target cell was increased. The preferential action of chondroitin sulfate E on the function of aP during the formation and decay of C3b,Bb,aP as compared to C3b,Bb,nP implies functional differences in the two forms of P even when they have been incorporated into C3b,Bb. The equal potency, when adjusted for uronic acid content, of chondroitin sulfate E proteoglycan isolated from the T cell-dependent, bone marrow-derived murine mast cell and of chondroitin sulfate E glycosaminoglycan from squid reveals that the linkage of the glycosaminoglycan to a peptide core does not diminish its regulatory action on the alternative complement pathway.     

Structure of linkage region between chondroitin polysulfates and peptides

Three different types of chondroitin polysulfate-peptide, chondroitin sulfate D-peptide, chondroitin sulfate E-peptide, and chondroitin sulfate K-peptide, all contained xylose, galactose, and serine in a molar ratio of about 1 : 2 : 1. After treatment with alkali in the presence of NaBH4 and PdCl2, they produced alanine and xylitol in amounts equivalent to the decrease in the amount of serine. Consequently, it was proved that these chondroitin polysulfates are all linked to peptides by O-glycosidic bonds between xylose and serine, as in chondroitin sulfates A and C. It is suggested that the carbohydrate-peptide linkage regions have the same structure in all the chondroitin sulfates, regardless of differences in the structure of the polysaccharide chains, such as the position of sulfate groups and the degree of sulfation.     

A chitin sulfate-like polysaccharide from the test of the tunicate Halocynthia roretzi

Considerable amounts of water-soluble polysaccharides were found in the test of the tunicate Halocynthia roretzi. After fractionation with ethanol, a chitin sulfate-like polysaccharide was isolated. From the results of chemical analysis, optical rotation, infrared spectrum and alkaline treatment, it is suggested that the predominant structure for this polysaccharide is (1→4)-2-acetamido-2-deoxy-6-O-sulfo-β-D-glucopyranan.     

Can Camera Traps Monitor Komodo Dragons a Large Ectothermic Predator?

Camera trapping has greatly enhanced population monitoring of often cryptic and low abundance apex carnivores. Effectiveness of passive infrared camera trapping, and ultimately population monitoring, relies on temperature mediated differences between the animal and its ambient environment to ensure good camera detection. In ectothermic predators such as large varanid lizards, this criterion is presumed less certain. Here we evaluated the effectiveness of camera trapping to potentially monitor the population status of the Komodo dragon (Varanus komodoensis), an apex predator, using site occupancy approaches. We compared site-specific estimates of site occupancy and detection derived using camera traps and cage traps at 181 trapping locations established across six sites on four islands within Komodo National Park, Eastern Indonesia. Detection and site occupancy at each site were estimated using eight competing models that considered site-specific variation in occupancy (ψ)and varied detection probabilities (p) according to detection method, site and survey number using a single season site occupancy modelling approach. The most parsimonious model [ψ (site), p (site*survey); ω = 0.74] suggested that site occupancy estimates differed among sites. Detection probability varied as an interaction between site and survey number. Our results indicate that overall camera traps produced similar estimates of detection and site occupancy to cage traps, irrespective of being paired, or unpaired, with cage traps. Whilst one site showed some evidence detection was affected by trapping method detection was too low to produce an accurate occupancy estimate. Overall, as camera trapping is logistically more feasible it may provide, with further validation, an alternative method for evaluating long-term site occupancy patterns in Komodo dragons, and potentially other large reptiles, aiding conservation of this species.