background: the widespread utilization of antimicrobial compounds has caused emergence of resistant microorganisms in the world. hence, the research to probe the products with antimicrobial features has led to finding natural habitats and discovering new pharmaceutical products. methods: in this study, an attempt was made to explore the niche of novel habitat to isolate pyllospheric bacteria fr...

background: shigellosis is a leading cause of diarrhea in many developing countries and although the disease can be controlled and managed with antibiotics, the constant emergence of resistant species requiring ever newer antibacterial drugs make development of an effective vaccine necessary. the bacteria are highly contagious and since immunity to shigella is serotype-specific a multi-serotype...

background: quorum sensing (qs) is a mechanism used by bacteria to determine their physiological activities and coordinate gene expression based on cell to cell signaling. many bacterial physiological functions are under the regulation of quorum sensing such as virulence, luminescence, motility, sporulation and biofilm formation. the aim of the present study was to isolate and characterize quor...

LT-IIa and LT-IIb, the type II heat-labile enterotoxins of Escherichia coli, are closely related in structure and function to cholera toxin and LT-I, the type I heat-labile enterotoxins of Vibrio cholerae and E. coli, respectively. Recent studies from our group demonstrated that LT-IIa and LT-IIb are potent systemic and mucosal adjuvants. To determine whether binding of LT-IIa and LT-IIb to the...

Most of the heat-labile enterotoxin (LT) synthesized by Escherichia coli is cell associated; however, a small portion of LT (approximately 10%) is released by bacterial cells into the culture supernatant. The LT subunit B (LT-B) produced by a cloned LT-B gene (tox B) was released in amounts equal to the parent LT release. In contrast, no release of LT subunit A (LT-A) or its smaller derivatives...

bordetella pertussis is a gram negative bacterium that causes respiratory tract infection in human (whooping cough). pertussis toxin (pt) is the main component of current acellular pertussis vaccine and the s1 (subunit1) is the main immunogenic part of it. thus, s1 has been the target of many studies as a potent candidate of acellular vaccine against bordetella pertussis, lacking the side effec...

tissue plasminogen activator (tpa) is a serine protease, which is composed of five distinct structural domains with 17 disulfide bonds, representing a model of high-disulfide proteins in human body. one of the most important limitations for high yield heterologous protein production in escherichia coli (e. coli) is the expression of complex proteins with multiple disulfide bridges. in this stud...

background: gold nanoparticles (gnps) are used in imaging and molecular diagnostic applications. as the development of a novel approach in the green synthesis of metal nanoparticles is of great importance and a necessity, a simple and safe method for the synthesis of gnps using plant extracts of zataria multiflora leaves was applied in this study and the results on gnps’ anticancer activity aga...

background: vascular endothelial growth factor (vegf) is a coordinate regulator of physiological angiogenesis during embryogenesis, skeletal growth and reproductive functions. there are several types of vegf, including vegf165. vegfs stimulate endothelial cell growth, angiogenesis, and capillary permeability. low induction temperature is a major factor for expression of the recombinant vegf165 ...