Secretion of Streptomyces tendae antifungal protein 1 by Lactococcus lactis
Braz. j. med. biol. res
;
38(11): 1585-1592, Nov. 2005.
Article
in English
| LILACS
| ID: lil-414712
RESUMO
Lactococcus lactis, the model lactic acid bacterium, is a good candidate for heterologous protein production in both foodstuffs and the digestive tract. We attempted to produce Streptomyces tendae antifungal protein 1 (Afp1) in L. lactis with the objective of constructing a strain able to limit fungal growth. Since Afp1 activity requires disulfide bond (DSB) formation and since intracellular redox conditions are reportedly unfavorable for DSB formation in prokaryotes, Afp1 was produced as a secreted form. An inducible expression-secretion system was used to drive Afp1 secretion by L. lactis; Afp1 was fused or not with LEISSTCDA, a synthetic propeptide (LEISS) that has been described to be a secretion enhancer. Production of Afp1 alone was not achieved, but production of LEISS-Afp1 was confirmed by Western blot and immunodetection with anti-Afp1 antibodies. This protein (molecular mass 9.8 kDa) is the smallest non-bacteriocin heterologous protein ever reported to be secreted in L. lactis via the Sec-dependent pathway. However, no anti-fungal activity was detected, even in concentrated samples of induced supernatant. This could be due to a too low secretion yield of Afp1 in L. lactis, to the absence of DSB formation, or to an improper DSB formation involving the additional cysteine residue included in LEISS propeptide. This raises questions about size limits, conformation problems, and protein secretion yields in L. lactis.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Bacterial Proteins
/
Carrier Proteins
/
Lactococcus lactis
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2005
Type:
Article
/
Project document
Affiliation country:
Brazil
/
France
Institution/Affiliation country:
Agrocampus National Institute for Agricultural Research/FR
/
Universidade Federal de Minas Gerais/BR
/
Universidade Federal do Rio Grande do Norte/BR
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