Insect Immunity. Purification and Properties of Three Inducible Bactericidal Proteins from Hemolymph of Immunized Pupae of Hyalophora cecropia

Abstract

Three inducible bacteriolytic proteins, designated P7, P9A and P9B, from the hemolymph of immunized pupae of the giant silk moth Hyalophora cecropia have been purified using a two‐step procedure with cation‐exchange chromatography. Purified protein P7 has a molecular weight of 15000 and its amino acid composition shows a great similarity to that of the lysozyme from the wax moth Galleria mellonella. Moreover, heat stability, pH‐rate profile and bacteriolytic specificity also indicate that protein P7 is a lysozyme. The other purified proteins, P9A and P9B, are highly potent against Escherichia coli and some other gram‐negative bacteria. The amino acid compositions of proteins P9A and P9B are very similar, although the contents of glutamic acid and methionine were different. The molecular weights of these very basic proteins are around 7000. The P9 proteins are heat stable; their activities were retained after 30 min incubation at 100°C. Both forms of protein P9 clearly differ from the lysozyme class of enzymes and they may represent a new type of bacteriolytic protein.

Insect proteins as a potential source of antimicrobial peptides in livestock production. A review

“…Until now, more than 1,500 proteins with antimicrobial activity have been found and identified in different organisms such as plants, fungi, bacteria and animals, however they are mainly present in insects (Yi et al, 2014). The antibacterial activity of insects was first observed in the pupae of the giant silk moths Samia cynthia and Hyalophora cecropia (Boman et al, 1974;Faye et al, 1975), and the first insect AMP (cecropin) was extracted from the pupae of H. cecropia in 1980 (Hultmark et al, 1980;Steiner et al, 1981). Since then, over 150 insect AMPs have been identified (Yi et al, 2014).…”

Diversity in penaeidin antimicrobial peptide form and function

“…Class 1 has since been defined as a class 2 variant [35,36]. This approach followed similar experiments that successfully sought antimicrobials and other natural products from arthropods [10,43,44]. In fact, using this type of screen, fragments of the oxygen transport protein hemocyanin, which are increased in hemolymph after stimulation, were found to have anti-MP properties [45].…”

Immunotoxic effect of Benzo[α]Pyrene and chrysene in juvenile white shrimp Litopenaeus vannamei

“…Antibacterial activity and bacteriolytic activity in hemolymph were measured using V. anguillarum and Micrococcus lysodeikticus (Sigma) respectively, following the modified methods of Hultmark [23] and shrimp pathogenic bacteria Vibro harveyi were used for antibacterial activity, and the bacteria Micrococcus lysoleikticus for bacteriolytic activity. Firstly, the cryopreserved liquid Vibro harveyi strains were thawed and inoculated and spread on the solid tryptone soy broth (TSB) medium containing 1.5% tryptone, 0.5% soy peptone and 2% NaCl with 1.5% agar and pH 7.2±0.2, afterwards the bacteria were incubated at 37°C for 24 h and next the bacteria were washed down gently from the plate into a new sterile tube by sterile 0.1 M phosphate buffer solution (PSB, pH 6.4), and finally prepared into a suspension with a certainconcentration (OD 570nm =0.3-0.5).…”