Esterase activity of Bordetella pertussis CyaC-acyltransferase against synthetic substrates: implications for catalytic mechanism in vivo.

Adenylate cyclase-hemolysin toxin (CyaA) produced from the human respiratory tract pathogen Bordetella pertussis requires fatty-acyl modification by CyaC-acyltransferase to become an active toxin. Previously, the recombinant CyaA pore-forming (CyaA-PF) fragment expressed in Escherichia coli was shown to be hemolytically active upon palmitoylation in vivo by cosynthesized CyaC. Here, the 21-kDa CyaC enzyme separately expressed in E.

Expression and immunoprotective property of a 39-kDa PlpB protein of Pasteurella multocida.

Pasteurella multocida is a Gram-negative bacterium known to infect a wide range of domestic and wild animals. The increasing incidence of P. multocida isolated from cases of fowl cholera and hemorrhagic septicemia has led to a renewed interest in this pathogen as well as in the development of vaccines.

HIV-1 Tat raises an adjuvant-free humoral immune response controlled by its core region and its ability to form cysteine-mediated oligomers.

Proteins are poor immunogens that require an adjuvant to raise an immune response. Here we show that the human immunodeficiency virus, type 1 Tat protein possesses an autoadjuvant property, and we have identified the determinants and the molecular events that are associated with this unusual property. Using a series of chemically synthesized Tat101 derivatives, we show that the core region controls the autoadjuvant phenomenon independently of the B-cell recognition and T-cell stimulation that are associated with epitopes respectively located on the N-terminal region and the cysteine-rich region.