572 research outputs found
Alien Registration- Akerley, Basil (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/30836/thumbnail.jp
Alien Registration- Akerley, Elizabeth (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/30988/thumbnail.jp
Alien Registration- Akerley, Verna (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/31069/thumbnail.jp
Alien Registration- Akerley, Dora F. (Auburn, Androscoggin County)
https://digitalmaine.com/alien_docs/30837/thumbnail.jp
Alien Registration- Akerley, Howard J. (Lewiston, Androscoggin County)
https://digitalmaine.com/alien_docs/30284/thumbnail.jp
Structure of YraM, a protein essential for growth of Haemophilus influenzae
Nontypeable Haemophilus influenzae is an obligate human parasite that often causes middle ear infections in children and exacerbates chronic obstructive pulmonary disorder, the fourth leading cause of death in the United States. There are no effective vaccines available for this strain. The lipoprotein YraM (gene HI1655) was identified as essential for the growth and viability of H. influenzae but its function is unknown. Sequence comparisons showed that YraM is a fusion of two protein modules. We grew crystals of the carboxyl-terminal module of YraM comprising residues 257–573 (YraM-C), phased the diffraction data by the multiwavelength anomalous diffraction technique, and refined the model to a crystallographic R -factor of 0.16 ( R free = 0.19) with data to 1.35 Å resolution. The two-domain structure of YraM-C adopts a fold similar to that observed for the open, unliganded forms of several periplasmic binding proteins (PBPs) involved in bacterial active transport. Sequence alignments of YraM homologues from other Gram-negative species showed that the most conserved residues of YraM-C cluster between the two domains in the location where other PBPs bind their cognate ligand. Modeling of YraM-C into a closed conformation similar to the leucine-bound form of the Leu/Ile/Val-binding protein (LIVBP) shows a putative binding pocket larger than the leucine-binding site in LIVBP. The pocket has both polar and nonpolar surfaces, with the latter located in the same area where a leucine side chain binds to LIVBP. We discuss possible biological functions of YraM considering its predicted location in the outer membrane, a novel place for such a binding protein. Proteins 2008. © 2008 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60983/1/22033_ftp.pd
Outer membrane protein P5 is required for resistance of nontypeable Haemophilus influenzae to both the classical and alternative complement pathways
The complement system is an important first line of defense against the human pathogen Haemophilus influenzae. To survive and propagate in vivo, H. influenzae has evolved mechanisms for subverting this host defense, most of which have been shown to involve outer surface structures, including lipooligosaccharide glycans and outer surface proteins. Bacterial defense against complement acts at multiple steps in the pathway by mechanisms that are not fully understood. Here we identify outer membrane protein P5 as an essential factor in serum resistance of both H. influenzae strain Rd and nontypeable H. influenzae (NTHi) clinical isolate NT127. P5 was essential for resistance of Rd and NT127 to complement in pooled human serum. Further investigation determined that P5 expression decreased cell surface binding of IgM, a potent activator of the classical pathway of complement, to both Rd and NT127. Additionally, P5 expression was required for NT127 to bind factor H (fH), an important inhibitor of alternative pathway (AP) activation. Collectively, the results obtained in this work highlight the ability of H. influenzae to utilize a single protein to perform multiple protective functions for evading host immunity
Just Been Wond\u27ring All Day Long
Title Onlyhttps://scholarsjunction.msstate.edu/cht-sheet-music/7791/thumbnail.jp
Transposon mutagenesis of Campylobacter jejuni identifies a bipartite energy taxis system required for motility
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73261/1/j.1365-2958.2001.02376.x.pd
Defining the Binding Region in Factor H to Develop a Therapeutic Factor H-Fc Fusion Protein against Non-Typeable Haemophilus influenzae
Non-typeable Haemophilus influenzae (NTHi) cause a range of illnesses including otitis media, sinusitis, and exacerbation of chronic obstructive pulmonary disease, infections that contribute to the problem of antibiotic resistance and are themselves often intractable to standard antibiotic treatment regimens. We investigated a strategy to exploit binding of the complement inhibitor Factor H (FH) to NTHi as a functional target for an immunotherapeutic containing the NTHi binding domain of FH fused to the Fc domain of IgG1. Chimeric proteins containing the regions that most FH-binding bacteria use to engage human FH, domains 6 and 7 (FH6,7/Fc) and/or 18 through 20 (FH18-20/Fc), were evaluated for binding to NTHi. FH6,7/Fc bound strongly to each of seven NTHi clinical isolates tested and efficiently promoted complement-mediated killing by normal human serum. FH18-20/Fc bound weakly to three of the strains but did not promote complement dependent killing. Outer-membrane protein P5 has been implicated in FH binding by NTHi, and FH6,7/Fc binding was greatly diminished in five of seven P5 deficient isogenic mutant strains tested, implicating an alternative FH binding protein in some strains. Binding of FH18-20/Fc was decreased in the P5 mutant of one strain. A murine model was used to evaluate potential therapeutic application of FH6,7/Fc. FH6,7/Fc efficiently promoted binding of C3 to NTHi exposed to mouse serum, and intranasal delivery of FH6,7/Fc resulted in significantly enhanced clearance of NTHi from the lung. Moreover, a P5 deficient mutant was attenuated for survival in the lung model, suggesting that escape mutants lacking P5 would be less likely to replace strains susceptible to FH6,7/Fc. These results provide evidence for the potential utility of FH6,7/Fc as a therapeutic against NTHi lung infection. FH binding is a common property of many respiratory tract pathogens and FH/Fc chimeras may represent promising alternative or adjunctive therapeutics against such infections, which are often polymicrobial
- …