Chemistry: molecular biology and microbiology – Micro-organism – per se ; compositions thereof; proces of... – Fungi
Reexamination Certificate
1999-03-03
2002-06-11
Navarro, Mark (Department: 1645)
Chemistry: molecular biology and microbiology
Micro-organism, per se ; compositions thereof; proces of...
Fungi
C530S300000, C530S326000, C530S344000, C530S350000, C530S820000, C530S823000
Reexamination Certificate
active
06403362
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for a large amount of expression or secretion of a protein or peptide in Humicola microorganisms, in particular,
Humicola insolens.
2. Description of the Related Art
Mold fungi is known to secrete proteins extracellularly. Thus, has been studied for developing highly productive mutant cells and processes for efficient production of proteins.
A typical example of such studies is to artificially create mutants by exposure to ultraviolet rays or by the use of a mutagen, and to select a strain which produces the target protein in a large volume.
However, these techniques may not be suitable for expressing an enzyme whose activity relies on the coordination of several different proteins, or for improving the characteristics of such an enzyme. Furthermore, when producing a protein which imparts a lethal or adverse effect on the growth of a host cell, the productivity of the target protein is generally difficult to increase by a mutation.
On the other hand, the recent progress in the study of genetic recombination for producing a target protein have enabled a large amount of production for heterogenous proteins, as well as proteins endogenous to the host cells but expressed only in small amounts. Successful production ranging from about 1.0 to 3.3 g per one liter of culture has been reported in some mold fungi, such as
Aspergillus nidulans
(G. L. Gray, et al., Gene, 48,41, 1986),
Aspergillus oryzae
(T. Christensen, et al., Bio/Technology, 6, 1419, 1988),
Trichoderma reesei
(Taina Karhunen, et al., Mol. Gen. Genet. 241, 515-522, 1993), and
Trichoderma viride
(C. Cheng, et al., Agric. Biol. Chem., 55, 1817, 1991).
Humicola insolens
is another example of a halophilic mold fungus having remarkable capability of protein secretion. This species is also known to produce various types of cellulase of industrial utility (WO91/17243 (Japanese Patent Laid-Open No. 5-509223)).
However, the useful content of the protein secretion from
Humicola insolens
accounts only for a few percent. If a process which enables fungus to express and secrete these small proportions of useful components in a large quantity is established, the benefit of the final products can be dramatically improved. Furthermore, a process that would enable a large quantity of expression of heterogenous genes in
Humicola insolens
may allow various enzymes and useful proteins to be produced in a single-step procedure, helping lower the cost of production. In addition, since
Humicola insolens
is a halophilic mold fungus with an optimum incubation temperature of about 37° C., it is hardly contaminated by other germs during incubation, making it further advantageous as a host for producing useful proteins.
Furthermore, systems for transforming
Humicola insolens
have been established, as has been disclosed by some of the inventors in Japanese Patent Laid-Open No. 8-56663, allowing the fungus to be used for genetic recombination.
Still, it has been awaited to develop an effective expression vector system which allows
Humicola insolens
to express and secrete a target protein at a high yield.
SUMMARY OF THE INVENTION
The inventors have now established a process for producing a target protein in a large quantity in Humicola, in particular,
Humicola insolens.
Thus, the object of the present invention is to a provide expressing systems enabling production of a protein in a large amount in Humicola, in particular,
Humicola insolens
, and particularly host-vector systems and a process for producing a protein using the host-vector systems.
Moreover, according to the preferred embodiment of the present invention, there is provided a highly efficient system for producing a protein, in which the productivity of the target protein is as high as about 4.5 g per one liter of culture, or 10 to 16 times that in the original strain.
REFERENCES:
patent: 0495554 (1992-07-01), None
patent: 59-175889 (1984-10-01), None
patent: 08-056663 (1996-03-01), None
patent: 08-126492 (1996-05-01), None
Aoyagi Kaoru
Hamaya Toru
Koga Jinichiro
Kono Toshiaki
Moriya Tatsuki
Meiji Seika Kaisha Ltd.
Navarro Mark
Varndell & Varndell PLLC
LandOfFree
Systems for the mass production of proteins or peptides by... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Systems for the mass production of proteins or peptides by..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Systems for the mass production of proteins or peptides by... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2912275