ABSTRACT
A novel serine protease inhibitor peptide family, designated as the 'pacifastin family', has recently been described in insects (locusts, lepidopterans) and crustaceans (crayfish). This study presents the cDNA cloning of two isoforms of SGPP-3, a novel pacifastin-related precursor in the desert locust, Schistocerca gregaria, which codes for three putative inhibitor peptides. The precursor isoforms differ at a single amino acid position in the third, C-terminal peptide. Northern blot analysis confirmed the presence of two different transcripts (0.75 and 0.90 kb). Both transcripts are most abundant in the fat body and appear to be strongly regulated during the moulting cycle. In addition, the amount of transcript proved to be strictly regulated in the ovaries during the female reproductive cycle.
Subject(s)
Grasshoppers/genetics , Insect Proteins/genetics , Protein Precursors/genetics , Proteins/genetics , Amino Acid Motifs/genetics , Amino Acid Sequence , Animals , Base Sequence , Blotting, Northern , Cloning, Molecular , DNA, Complementary/chemistry , DNA, Complementary/genetics , Female , Gene Expression Regulation, Developmental/genetics , Grasshoppers/growth & development , Grasshoppers/metabolism , Insect Proteins/biosynthesis , Insect Proteins/chemistry , Male , Molecular Sequence Data , Protein Biosynthesis , Protein Isoforms , Protein Precursors/biosynthesis , Protein Precursors/chemistry , Proteins/chemistry , Reverse Transcriptase Polymerase Chain Reaction , Sequence Analysis, DNA , Sequence Homology, Amino AcidABSTRACT
The extracts of 12 plants selected on the basis of the folk-medicine reports were examined for their antibacterial effects against eight pathogenic bacteria. The n-butanol extract of Calotropis procera flowers and the aqueous extract of Eugenia caryophyllata proved to be the most effective against the bacteria tested.
Subject(s)
Bacteria/drug effects , Magnoliopsida , Plants, Medicinal , Humans , Medicine, African Traditional , Microbial Sensitivity Tests , Morocco , Phytotherapy , Plant Extracts/pharmacologyABSTRACT
The extracts of six plants selected on the basis of folk-medicine reports were examined for their antibacterial effects against eight pathogenic bacteria. The results showed that n-butanol extract of Calotropis procera proved to be the most effective against the bacteria tested using the paper disc diffusion method. The antiprotozoal activity was also examined and showed that ethyl ether extract of Sium nodiflorum exhibits a parasiticidal effect against Trichomonas intestinalis and vaginalis.
Subject(s)
Anti-Bacterial Agents/pharmacology , Antiprotozoal Agents/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Trichomonas/drug effects , 1-Butanol , Animals , Anti-Bacterial Agents/isolation & purification , Antiprotozoal Agents/isolation & purification , Ether , Eukaryota/drug effects , Hexanes , Microbial Sensitivity Tests , Morocco , Solvents , Species Specificity , Trichomonas vaginalis/drug effects , WaterABSTRACT
This study describes the cloning of two cDNAs encoding three serine-protease-inhibiting peptides, SGPI I, II and III, which were recently identified from ovarian extracts of the desert locust, Schistocerca gregaria. The first cDNA codes for the precursor polypeptides of SGPI I and SGPI II; the second encodes only a single inhibitor, SGPI III. Northern-blot analysis revealed an approximate length of 0.8 kb for SGPI-I/II mRNA and 0.6 kb for SGPI-III mRNA. The transcripts are present in several locust tissues, but they could not be detected in the midgut. The gene for SGPI-I/II is abundantly transcribed during all larval and adult stages, whereas SGPI-III mRNA is mainly present in adults. Northern-blot hybridization also revealed important changes in the SGPI-mRNA content during the molting cycle and during the adult reproductive cycle. Moreover, a differential hormonal control was observed in adult females which had been treated with precocene, juvenile hormone or ecdysone.
Subject(s)
Grasshoppers/physiology , Insect Proteins/chemistry , Peptides/chemistry , Serine Proteinase Inhibitors/chemistry , Amino Acid Sequence , Animals , Base Sequence , Benzopyrans/pharmacology , Cloning, Molecular , Ecdysterone/pharmacology , Female , Gene Expression Regulation, Developmental/genetics , Molecular Sequence Data , Ovary/chemistry , Protein Precursors/chemistry , RNA, Messenger/metabolism , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Sesquiterpenes/pharmacology , Transcription, Genetic/geneticsABSTRACT
The ovary of the desert locust, Schistocerca gregaria, contains multiple inhibitors of serine proteases. Five serine protease inhibitors, designated SGPI-1-5 (Schistocerca gregaria protease inhibitors) were purified from methanolic extracts of mature ovaries and analyzed by mass spectrometry and amino acid sequencing. The revealed primary structures display amino acid similarities and are related to the serine protease inhibitors identified in the hemolymph of Locusta migratoria. All inhibitors show an in vitro inhibiting activity towards alpha-chymotrypsin. In addition, SGPI-1 displays in vitro inhibiting activity towards trypsin, and SGPI-2 is a potent pancreatic elastase inhibitor. Differences in inhibitory specificities towards the locust endogenous serine proteases can be readily attributed to the amino acid sequence within the active region and also to amino acid residues beyond the P1-P'1 bond. A difference in one or two amino acid residues around the reactive sites results in considerable alteration of the inhibitory specificity. The temporal and spatial distribution of SGPI-1-5 was studied by RP-HPLC analysis. All inhibitors occur in hemolymph, ovaries, testes and fat body of adults but are absent in the gut. They are also present in larval hemolymph and fat body. An antibody raised against SGPI-2 shows positive immunostaining in the ovarian follicle cells.
