INVESTIGADORES
ALVAREZ Hector Manuel
artículos
Título:
Preparative isolation of lipid inclusions from Rhodococcus opacus and Rhodococcus ruber and identification of granule-associated proteins
Autor/es:
KALSCHEUER R,; WÄLTERMANN M,; ALVAREZ, H. M.; STEINBÜCHEL A,
Revista:
ARCHIVES OF MICROBIOLOGY
Editorial:
Springer
Referencias:
Lugar: Berlin; Año: 2001 vol. 177 p. 20 - 28
ISSN:
0302-8933
Resumen:
Abstract Triacylglycerol granules synthesized and accumulated
by Rhodococcus opacus and Rhodococcus ruber
were isolated by glycerol density gradient centrifugation.
Whereas only one type of granule could be isolated from
R. opacus, two types of granules with different specific
densities were isolated from R. ruber. Both types of R. ruber
granules showed a similar content of triacylglycerols
and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), but the
protein profiles of both types were significantly different.
The granules with the lower specific density were colorless;
the granules with the higher specific density had a
deep orange pigmentation. Solubilization studies revealed
three different groups of granule-associated proteins: (1)
unspecifically bound proteins, (2) relatively weakly associated
proteins, and (3) proteins that resisted solubilization
by treatment with 2 M NaCl, 2% (w/v) Triton X-114,
6 M guanidinium hydrochloride, up to 8% (w/v) SDS, and
proteolytic digestion. The strong association of proteins
of the last group suggested that these may play a specific
role in the synthesis or mobilization of storage lipids or in
the structure of the granules. The N-terminal amino acid
sequences of the most tightly bound proteins were obtained.
Proteins of low molecular weight with striking sequence
similarity to the ribosomal protein L7 from various actinomycetes
were always copurified with the granules.