Isolation, Structural Characterization, and Properties of Mattacin (Polymyxin M), a Cyclic Peptide Antibiotic Produced byPaenibacillus kobensis M

Abstract

Mattacin is a nonribosomally synthesized, decapeptide antibiotic produced by Paenibacillus kobensis M. The producing strain was isolated from a soil/manure sample and identified using 16 S rRNA sequence homology along with chemical and morphological characterization. An efficient production and isolation procedure was developed to afford pure mattacin. Structure elucidation using a combination of chemical degradation, multidimensional NMR studies (COSY, HMBC, HMQC, ROESY), and mass spectrometric (MALDI MS/MS) analyses showed that mattacin is identical to polymyxin M, an uncommon antibiotic reported previously in certain Bacillus species by Russian investigators. Mattacin (polymyxin M) is cyclic and possesses an amide linkage between the C-terminal threonine and the side chain amino group of the diaminobutyric acid residue at position 4. It contains an (S)-6-methyloctanoic acid moiety attached as an amide at the N-terminal amino group, one D-leucine, six L-␣,␥-diaminobutyric acid, and three L-threonine residues. Transfer NOE experiments on the conformational preferences of mattacin when bound to lipid A and microcalorimetry studies on binding to lipopolysaccharide showed that its behavior was very similar to that observed in previous studies of polymyxin B (a commercial antibiotic), suggesting an identical mechanism of action. It was capable of inhibiting the growth of a wide variety of Gram-positive and Gramnegative bacteria, including several human and plant pathogens with activity comparable with purified polymyxin B. The biosynthesis of mattacin was also examined briefly using transpositional mutagenesis by which 10 production mutants were obtained, revealing a set of genes involved in production.

Interactions of Lipopolysaccharide and Polymyxin Studied by NMR Spectroscopy

“…Their data highlight the importance of electrostatic interactions between phosphate groups and amino groups of polymyxin as well as hydrophobic interactions of the lipid chains with Phe or Leu residues. Martin et al (19) have studied the structure of LPSbound PMX-M, which displayed a chair-like conformation, in which the side chain of Dab-4 or -8 and Leu-6 or Thr-7 point into the opposite directions in a fashion similar to that proposed for PMX-B and -E (19). Pristovsek determined the structure of a LPS-bound synthetic fragment of the LALF protein (10) revealing a hairpin-type fold, again characterized by spatial separation of hydrophobic and cationic residues.…”

“…Small wells (ϳ4.6-mm diameter) were made in the seeded agar plates, and 50 l of filtered culture supernatant was added to the wells. Plates were incubated at 30°C, and the growth of the indicator organism was visible after ϳ3 h (19).…”

Lipopeptides as anti-infectives: a practical perspective

“…Polymyxin B and polymyxin E (also known as colistin), both produced by the bacterium Bacillus polymyxa, have been known for decades and are the best studied examples, but novel compounds belonging to this class, such as polymyxin M (mattacin) isolated from Paenibacillus kobensis, continue to be discovered [5].…”

Characterization of an Indigenous Antimicrobial Substance-producing Paenibacillus sp. BCNU 5011

“…Paenibacillus polymyxa로부터 분리 된 항생물질은 대부분 펩타이드계로서 polymixin A, B, E (colistin), polipeptins, jolipeptins, gatavalin, gavaserin 그리 고 saltavalin은 그람양성 및 음성세균에 대하여 활성을 나 타내는 것으로 보고되어 있으며, LI-F 복합체와 fusaricidins A-D는 진균과 그람 양성 세균에 대하여 활성을 나타낸다고 보고되어 있다 [8][9][10][11]. 그 외 circulin, lantibiotic 등 [12,13] 도 생산되고 있음이 보고되고 있으며, P. kobensis M으로 부터 분리된 polymyxin M (mattacin), P. thiamunolyticus 로부터 octopygtin과 baciphelacin 등이 분리 보고되고 있 다 [14,15]. P. polymyxa 균주가 생산하는 polymyxin은 그람 음성 세균에 대한 강력한 항균효과를 나타냄으로써 1970년 대 초반까지 병원성 미생물에 의한 질병 치료제로서 많이 사용되어 왔으나, 신경독성과 간독성 등의 부작용을 동반하 여 그 사용이 줄어들었다 [16,17].…”