Background: Bactenecin is one of the smallest cationic eukaryotic antimicrobial peptides (AMPs) with a length of 12 residues and a beta-turn structure originated from bovine neutrophil cells. Previous studies reported poor capability of this peptide against Gram-negative bacteria. Objectives: The present study aimed at investigating the bactenecin bactericidal activity and determining the effect of increasing the positive charge of amine and carboxyl terminus and increasing the hydrophobicity of the central part of the antimicrobial peptide. Methods: Similar to the native peptide, three designed variants were employed named BM1, BM2, and BM3 that had increased positive charges, hydrophobicity, and a combination of both, respectively. Conditions for purifying and assaying their antibacterial activity against Gram-negative bacteria were predicted and optimized by APD3 and ExPASy servers. The cloned and expressed peptides in Pichia pastoris GS115 were partially purified by anion and cation exchange chromatography. The final purification rate of AMPs by HPLC was reported to be 70% and peptides were further characterized by LC-mass analysis. Finally, a minimum inhibitory concentration test was conducted. Results: The results implied the more significant effect of positive charges on the performance of these peptides against Escherichia coli.

Background:Mutations in the acid alpha-glucosidase (GAA) gene usually lead to reduced GAA activity. In this study, we analyzed the mutations of GAA and GAA enzyme activity from one sibling suspected Pompe disease and their first-degree relatives.Materials and Methods:In this cross-sectional study, GAA enzyme activity assay was assessed using tandem mass spectrometry. Polymerase chain reaction and Sanger sequencing were performed for GAA analysis.Results:GAA enzyme activity was significantly decreased in patients compared to the normal range (P = 0.02). Two individuals showed ten alterations in the GAA sequence, in which one of them (c. 1650del G) has not been previously described in the literature. A single Guanine deletion (del-G) was detected at codon 551 in exon 12.Conclusion:According to the literature, the detected change is a novel mutation. We hypothesized that the discovered deletion in the GAA might lead to a reduced activity of the gene product.