BioMed Research International

Research Article

Antibacterial Activity of Synthetic Peptides Derived from Lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212

Table 1

Synthetic peptides derived from lactoferricin protein. Summary of characterization (RP-HPLC and MALDI-TOF MS) and antibacterial activity of purified products.


Group	Peptide code	Sequence	RP-HPLC (min)	MALDI-TOF MS		E. coli ATCC 25922		E. faecalis ATCC 29212
Group	Peptide code	Sequence	RP-HPLC (min)	Theoretical Mol wt	Experimental m/z. [M + H]⁺	MIC (M)	MCB (M)	MIC (M)	MCB (M)

I	I	RRWQWR	16,73	985,54	986,92	101,5	101,5	202,9	202,9
	I.1	RRWQWR	16,28	1057,56	1057,27	94,6	189,1	189,1	189,1
	I.2	RWQWRWQWR	22,84	1485,75	1487,12	26,9	33,7	26,9	33,7
	I.3	RWQWRWQWR	22,47	1556,79	1558,16	64,2	64,2	32,1	32,1
	I.4	((RRWQWR)₂KC)₂	20,00	4596,64	2300,57^a	4,4	4,4	10,9	10,9

II	II.1	¹⁷FK¹⁹CRRWQWRMKKLG³¹A	19,30	1993,49	1995,02	25,1	25,1	25,1	25,1
	II.2	FKRRWQWRMKK	17,42	1718,97	1721,12	29,1	29,1	116,3	116,3
	II.3	FK RRWQWRMKK	17,81	1718,97	1720,81	116,3	116,3	58,2	116,3
	II.4	FK RRWQWRM	19,51	1462,78	1464,73	34,2	34,2	68,4	136,7
	II.5	FKRRWQWRM	19,17	1462,78	1464,51	68,4	136,7	136,7	136,7
	II.6	FK RWQWRM	20,13	1420,75	1420,93	70,4	70,4	140,8	140,8
	II.7	FK WQWRM	23,14	1377,72	1377,9	145,2	145,2	145,2	145,2
	II.8	RRWQWRMKKLG	18,31	1542,87	1545,12	32,4	32,4	64,8	129,6
	II.9	RRWQWRMKKLG	18,19	1613,91	1615,3	123,9	123,9	62,0	123,9
	II.10	RRWQWRMLG	18,52	1669,92	1672,64	59,9	59,9	15,0	29,9
	II.11	RRWQWRMKK	17,17	1443,80	1445,08	69,3	69,3	69,3	69,3

III	III.1	²⁰GRRRRSVQWC³⁰A	16,00	1372,73	1373,6	18,2	36,4	72,8	145,7
	III.2	GRRRRSVQWCA	14,81	1516,76	1515,98	65,9	65,9	65,9	131,9
	III.3	GRRRRSVQWCA	15,15	1445,68	1144,93	69,2	138,3	69,2	138,3
	III.4	GRRRRSVQWCA	15,20	1443,76	1444,82	17,3	34,6	69,3	138,5

IV	IV.1	FKCRRWQWRMKKLGAPSITCVRRAE	19,12	3104,66	3106,15	32,2	32,2	32,2	32,2
	IV.2	LF protein	—	80000	—	25,0	25,0	25,0	25,0
	IV.3	ITEVEPEDIDT	15,02	1258,58	1259,99	1589,1	1589,1	1589,1	1589,1

This signal corresponds to the dimer before oxidation (see Figure 2). The reported antimicrobial LfcinB center [24, 25] is underlined and changes in amino acid sequences are in box.