title: Native N-terminus nitrophorin 2 from the kissing bug: similarities to and differences from NP2(D1A).
abstract: The first amino acid of mature native nitrophorin 2 is aspartic acid, and when expressed in E. coli, the wild-type gene of the mature protein retains the methionine-0, which is produced by translation of the start codon. This form of NP2, (M0)NP2, has been found to have different properties from its D1A mutant, for which the Met0 is cleaved by the methionine aminopeptidase of E. coli (R. E. Berry, T. K. Shokhireva, I. Filippov, M. N. Shokhirev, H. Zhang, F. A. Walker, Biochemistry 2007, 46, 6830). Native N-terminus nitrophorin 2 ((ΔM0)NP2) has been prepared by employing periplasmic expression of NP2 in E. coli using the pelB leader sequence from Erwinia carotovora, which is present in the pET-26b expression plasmid (Novagen). This paper details the similarities and differences between the three different N-terminal forms of nitrophorin 2, (M0)NP2, NP2(D1A), and (ΔM0)NP2. It is found that the NMR spectra of high- and low-spin (ΔM0)NP2 are essentially identical to those of NP2(D1A), but the rate and equilibrium constants for histamine and NO dissociation/association of the two are different.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Arizona, P.O. Box 210041, Tucson, AZ 85721-0041, USA. berryr@email.arizona.edu
authors.forename: Robert E
authors.initials: RE
authors.lastname: Berry
authors.forename: Dhanasekaran
authors.initials: D
authors.lastname: Muthu
authors.forename: Tatiana K
authors.initials: TK
authors.lastname: Shokhireva
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Garrett
authors.forename: Hongjun
authors.initials: H
authors.lastname: Zhang
authors.forename: F Ann
authors.initials: FA
authors.lastname: Walker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006418:Heme / Q000737:chemistry; D006420:Hemeproteins / Q000737:chemistry*; D019476:Insect Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D012239:Rhodnius / Q000737:chemistry* / Q000235:genetics; D012471:Salivary Proteins and Peptides / Q000737:chemistry*
chemical_list: D006420:Hemeproteins; D019476:Insect Proteins; D012471:Salivary Proteins and Peptides; C090560:nitrophorin; D006418:Heme