Related Experiment Video
Updated: Aug 25, 2026
Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae
Published on: February 24, 2023
Identification and initial characterization of a putative Mycoplasma gallinarum leucine aminopeptidase gene
Xiufeng Wan1, Scott L Branton, Larry A Hanson
1Department of Basic Sciences, College of Veterinary Medicine, Box 6100, Mississippi State University, Mississippi State, MS 39762, USA.
Abstract:
Aminopeptidases (APN) may play a role in host colonization of M. gallinarum. Characterization of endogenous APN activity suggests that the leucine APN (LAP) of M. gallinarum is a metallo-aminopeptidase activated by Mn2+ and is present in the cytosol and possibly associated with the inner leaflet of the membrane. A 1.36-kb open reading frame (ORF) identified from overlapping genomic phage clones showed 68% nucleotide identity and 51% amino acid identity with the M. salivarium LAP gene. This ORF is expressed as a 1.5-kb monocistronic transcript and is present as a single copy in M. gallinarum. This gene sequence was modified to account for codon usage, and expression in E. coli produced a 51-kDa protein, which compares well with the product predicted from the ORF. This ORF is a strong candidate for contributing the LAP activity of M. gallinarum protein extracts.
Insights
The leucine aminopeptidase (LAP) of M. gallinarum, a metalloenzyme, is crucial for host colonization. Its gene was identified and expressed in E. coli, confirming its role in M. gallinarum
Area of Science:
- Microbiology
- Molecular Biology
- Enzymology
Background:
- Aminopeptidases (APN) are implicated in microbial host colonization.
- The specific role of APN in Mycoplasma gallinarum (M. gallinarum) host interactions requires elucidation.
Purpose of the Study:
- To characterize the endogenous aminopeptidase activity in M. gallinarum.
- To identify and characterize the gene encoding the leucine aminopeptidase (LAP) of M. gallinarum.
Main Methods:
- Biochemical characterization of M. gallinarum protein extracts to identify APN activity.
- Genomic DNA analysis to identify the LAP gene.
- Gene cloning and expression in E. coli for protein characterization.
Main Results:
- M. gallinarum possesses metallo-aminopeptidase activity, specifically LAP, activated by Mn2+.
- A 1.36-kb open reading frame (ORF) with significant homology to M. salivarium LAP was identified.
- The identified ORF was expressed in E. coli, producing a 51-kDa protein consistent with LAP activity.
Conclusions:
- The characterized LAP is a strong candidate for mediating M. gallinarum's host colonization.
- The identified gene provides a molecular basis for understanding LAP function in M. gallinarum.
