Halotolerant aminopeptidase M29 from Mesorhizobium SEMIA 3007 with biotechnological potential and its impact on biofilm synthesis

Abstract

The aminopeptidase gene from Mesorhizobium SEMIA3007 was cloned and overexpressed in Escherichia coli. The enzyme called MesoAmp exhibited optimum activity at pH 8.5 and 45 °C and was strongly activated by Co2+ and Mn2+. Under these reaction conditions, the enzyme displayed Km and kcat values of 0.2364 ± 0.018 mM and 712.1 ± 88.12 s−1, respectively. Additionally, the enzyme showed remarkable stability in organic solvents and was active at high concentrations of NaCl, suggesting that the enzyme might be suitable for use in biotechnology. MesoAmp is responsible for 40% of the organism’s aminopeptidase activity. However, the enzyme’s absence does not affect bacterial growth in synthetic broth, although it interfered with biofilm synthesis and osmoregulation. To the best of our knowledge, this report describes the first detailed characterization of aminopeptidase from Mesorhizobium and suggests its importance in biofilm formation and osmotic stress tolerance. In summary, this work lays the foundation for potential biotechnological applications and/or the development of environmentally friendly technologies and describes the first solvent- and halo-tolerant aminopeptidases identified from the Mesorhizobium genus and its importance in bacterial metabolism.

From Data Mining of Chitinophaga sp. Genome to Enzyme Discovery of a Hyperthermophilic Metallocarboxypeptidase

“…Nevertheless, because ChtCP is active over a wide range of pH and temperature and particularly has increased activity at temperatures above 40 °C, understanding this enzyme is of great value for many biotechnological applications. In addition, the fact that ChtCP is more active at higher temperatures favors the increase in the solubility of the substrate and the product released [ 10 , 73 ]. Also, it should be noted that the conformational movements that are important for the activity of the enzymes require thermal energy.…”

“…Among the enzymes which have been discovered with this approach are endoglucanases, laccases, nitrilases, reductases and xylanases [ 9 ]. This is in addition to other enzymes of major industrial value such as peptidases [ 10 ], lipases [ 11 , 12 ] and ß-glucosidases [ 13 ]. This approach shows great potential for enzyme discovery from microorganisms.…”

An M29 Aminopeptidase from Listeria Monocytogenes Contributes to In Vitro Bacterial Growth but not to Intracellular Infection

“…Various effects of bacterial aminopeptidases on growth have been well elucidated to date. The Mesorhizobium AmpT has been found not required for growth in synthetic media but for biofilm production [6], whereas, in S. thermophilus, hawse have come to a conclusion that the M29 aminopeptidase PepS is involved in bacterial growth, both on rich media and chemically-defined media [5]. On the other hand, in L. lactis, inactivation of peptidases PepN, PepX, PepC, PepT, or PepO, or of all five, has no significant effect on bacterial growth on a rich medium [39].…”

“…Aminopeptidases (APs), one of the Mpl groups, can catalyze the cleavage of N-terminal amino acids in proteins or peptides, releasing amino acid residues, preferably the hydrophobic residues [5]. These peptidases are widely distributed in bacteria, fungi, and other species with important physiological roles, such as protein maturation, protein turnover, hydrolysis of regulatory peptides, nitrogen nutrition, modulation of gene expression, support of the amino acids pool, and virulence factors, and thus are considered essential enzymes [5][6][7][8][9][10]. Based on the hierarchical and structure-based classification of the peptidases, APs are divided into clans, MA, MF, MG, MH, MN, and MQ in the MEROPS database (also termed proteases, proteinases, and proteolytic enzymes) [11,12], and most aminopeptidases are metalloenzymes, except for prolyl aminopeptidase (serine peptidases) and DmpA aminopeptidase (nucleophile hydrolase) [12].…”

“…In addition to most of the studies focusing on the biochemical properties of the M29 family aminopeptidases, more researchers have increasingly been concentrating on the biological roles of this peptidase family. The aminopeptidase MesoAmp of the M29 family from Mesorhizobium has been found to play an important role in biofilm formation and osmotic stress tolerance [6]. The PepS from Streptococcus thermophilus has been demonstrated to play a pleiotropic role through its involvement in growth via nitrogen nutrition, as well as via other cellular functions or metabolisms [5].…”