Call number: LD2668 .T4 1963 G77 / Master of Science

Call number: LD2668 .T4 1963 K57 / Master of Science

Call number: LD2668 .T4 1964 B62 / Master of Science

Call number: LD2668 .T4 1965 S812 / Master of Science

No description available.

published_or_final_version / Zoology / Master / Master of Philosophy

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

No description available.

Seven strains of Actinobacillus suis (ATCC 15557, B49, C84, H89-1173, H91-0380, SO4 and VSB 3714) were investigated with respect to iron acquisition from animal transferrins (Tfs) and haemoglobins (Hbs). Growth assays with porcine, bovine and human Tfs and Hbs revealed that all seven strains could use porcine (but not human or bovine) Tf and all three Hbs as iron sources. In solid phase binding assays, membranes derived from all strains exhibited strong binding of porcine Tf and each of the Hbs. Competition binding assays indicated that all three Hbs were bound by the same receptor(s). Affinity procedures allowed the isolation and identification of iron repressible Tf-binding (~100 kDa and ~63 kDa) and Hb-binding (~105 kDa) polypeptides from all strains. Nucleotide sequence analyses revealed that A. suis strains SO4 and C84 possess genes that encode homologues of the Actinobacillus pleuropneumoniae Tf-binding proteins, TbpA and TbpB, and Hb-binding protein, HgbA. In both strains, tbpB was located immediately upstream of tbpA and was shown to be preceded by tonB, exbB and exbD homologues; hgbA was shown to be preceded by a hugZ homologue. Putative promoter and Fur box sequences were located upstream of tonB and hugZ and RT-PCR revealed that the genes in each of these clusters (tonB-exbB-exbD-tbpB-tbpA; hugZ-hgbA) are co-transcribed and iron-repressible. The molecular masses of the predicted mature TbpA, TbpB and HgbA proteins were calculated to be 104.3, 63.4 and 105.0 kDa, respectively, suggesting that the affinity-isolated, ~100 kDa and ~63 kDa Tf-binding polypeptides represent TbpA and TbpB, respectively, and that the ~105 kDa Hb-binding polypeptide represents HgbA. TbpB of A. suis was expressed in Escherichia coli and the recombinant TbpB (rTbpB) was identified by immunoblotting using swine sera raised against recombinant TbpB (A. pleuropneumoniae). It is envisaged that the acquisition of Tf- and Hb-bound iron by A. suis involves mechan

No description available.