Apolipoprotein A-I from striped bass (Morone saxatilis) demonstrates antibacterial activity in vitro.
HDL and apolipoprotein A-I from teleostean fishes demonstrate in vitro activity against gram-positive and gram-negative bacteria. In this study, we purified ApoA-1 from striped bass (Morone saxatilis) plasma and examined its in vitro antibacterial activity against Streptococcus sp., Escherichia coli, and Mycobacterium marinum. In addition, we obtained sequence for a putative striped bass ApoA-1 gene, which when translated contained the identical sequence generated from N-terminal sequencing of the purified ApoA-1. The predicted secondary and tertiary structures contained the characteristic proline residues and high alpha-helical content conserved between mammals and fishes. Purified ApoA-1 exhibited antibacterial activity against the bacteria assayed. Concentrations of 125 microg/mL for E. coli, 250 microg/mL for Streptococcus sp., and 250 microg/mL for M. marinum, inhibited bacterial growth by 50% compared to control. ApoA-1 plasma concentrations in experimental and wild fish ranged from undetectable levels to greater than 5 mg/mL, indicating that striped bass ApoA-1 is an effective antibacterial agent at concentrations below the range of physiological concentrations in striped bass plasma. We therefore conclude that ApoA-1 could play a role in innate defense against bacterial pathogens in striped bass.
Johnston
L Danielle
LD
Virginia Institute of Marine Science, College of William and Mary, 1208 Greate Road, Gloucester Point, Virginia 23062, United States. dani_johnston@mac.com
Brown
Gwynne
G
Gauthier
David
D
Reece
Kimberly
K
Kator
Howard
H
Van Veld
Peter
P
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology*; D016632:Apolipoprotein A-I / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology*; D001483:Base Sequence; D001492:Bass / Q000235:genetics / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology*; D017931:DNA Primers / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects; D029941:Fish Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology*; D007113:Immunity, Innate; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D019910:Mycobacterium marinum / Q000187:drug effects; D017386:Sequence Homology, Amino Acid; D013291:Streptococcus / Q000187:drug effects
D000900:Anti-Bacterial Agents; D016632:Apolipoprotein A-I; D017931:DNA Primers; D029941:Fish Proteins