title: Crystallization and preliminary X-ray analysis of Na-SAA-2 from the human hookworm parasite Necator americanus.
abstract: Human hookworms are among the most pathogenic soil-transmitted helminths. These parasitic nematodes have co-evolved with the host and are able to maintain a high worm burden for decades without killing the human host. However, it is possible to develop vaccines against laboratory-challenge hookworm infections using either irradiated third-state infective larvae (L3) or enzymes from the adult parasites. In an effort to control hookworm infection globally, the Human Hookworm Vaccine Initiative, a product-development partnership with the Sabin Vaccine Institute to develop new control tools including vaccines, has identified a battery of protein antigens, including surface-associated antigens (SAAs) from L3. SAA proteins are characterized by a 13 kDa conserved domain of unknown function. SAA proteins are found on the surface of infective L3 stages (and some adult stages) of different nematode parasites, suggesting that they may play important roles in these organisms. The atomic structures and function of SAA proteins remain undetermined and in an effort to remedy this situation recombinant Na-SAA-2 from the most prevalent human hookworm parasite Necator americanus has been expressed, purified and crystallized. Useful X-ray data have been collected to 2.3 A resolution from a crystal that belonged to the monoclinic space group C2 with unit-cell parameters a = 73.88, b = 35.58, c = 42.75 A, beta = 116.1 degrees .
authors.affiliation: Department of Pathology and Microbiology, College of Medicine, Nebraska Medical Center, Omaha, NE 68198-6495, USA. oasojo@unmc.edu
authors.forename: Oluwatoyin A
authors.initials: OA
authors.lastname: Asojo
authors.forename: Gaddam N
authors.initials: GN
authors.lastname: Goud
authors.forename: Bin
authors.initials: B
authors.lastname: Zhan
authors.forename: Katherine
authors.initials: K
authors.lastname: Ordonez
authors.forename: Meghan
authors.initials: M
authors.lastname: Sedlacek
authors.forename: Kohei
authors.initials: K
authors.lastname: Homma
authors.forename: Vehid
authors.initials: V
authors.lastname: Deumic
authors.forename: Richi
authors.initials: R
authors.lastname: Gupta
authors.forename: Jill
authors.initials: J
authors.lastname: Brelsford
authors.forename: Merelyn K
authors.initials: MK
authors.lastname: Price
authors.forename: Michelle N
authors.initials: MN
authors.lastname: Ngamelue
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hotez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D006801:Humans; D008969:Molecular Sequence Data; D017221:Necator americanus / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014961:X-Ray Diffraction
chemical_list: D000947:Antigens, Helminth