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Patent Issued for Auto-Developing and Regularly-Weighted Protein Molecular Weight Marker Kit and Method for Preparing the Same

August 12, 2014



By a News Reporter-Staff News Editor at Life Science Weekly -- Kaohsiung Medical University (Kaohsiung, TW) has been issued patent number 8791240, according to news reporting originating out of Alexandria, Virginia, by NewsRx editors (see also Kaohsiung Medical University).

The patent's inventors are Cheng, Tian-Lu (Kaohsiung, TW); Cheng, Chiu-Min (Kaohsiung, TW).

This patent was filed on February 22, 2012 and was published online on July 29, 2014.

From the background information supplied by the inventors, news correspondents obtained the following quote: "Protein markers play a crucial role in proteomics research with the coming of post-genome era. However, protein markers nowadays still have many restrictions and inconveniences. For example, (1) currently, the protein markers have to be copied manually from nitrocellulose paper to film instead of developing directly in the film during western blotting; (2) the common pre-stain protein markers sold on market have low-accuracy since the staining results in heterogeneity and electricity alteration; and (3) the current protein marker kits use known proteins as markers, yet their molecular weights are fixed and irregular. Therefore, there is a need for developing an auto-developing and regularly weighted protein molecular weight marker for Western blot to solve the problems encountered in proteomics research.

"There are presently various types of protein markers for electrophoresis and Western blotting, and most of them are pre-stain markers. For instance, the multicolored protein marker is known for its colorful marker that enables easy observation, but the low-accuracy problem is still unsolved.

"Chang et al. used a set of green fluorescent protein (GFP) fused proteins to construct dye-free protein molecular weight markers, which can emit fluorescence and present bands as regular as a ladder (Chang M., Hsu H. Y. and Lee H. J. Dye-free protein molecular weight markers. Electrophoresis, 26: 3062-68, 2005). Although the markers are convenience, they cannot be heated since GFP would be denatured and lose function. Without heating, however, the markers cannot be denatured thoroughly. Thus, the low-accuracy problem still remains.

"Biotinylated protein markers are also available. These markers are dye-free but additional biotin label is required. Moreover, in order to be detected by color reaction, there is a need of labeling with HRP-conjugated anti-biotin antibody or HRP-conjugated avidin, which causes many inconveniences. In addition, biotin labeling may also alter the electric charge of protein marker and result in inaccuracy.

"There are products of HIS-tag, S-tag or E-tag-fused protein markers as well. When using HIS-tag, S-tag, or E-tag antibodies to carry out development, the protein markers would auto-develop on film simultaneously. Those protein markers are not popular for the reason that the color presents simultaneously only when HIS-tag, S-tag, or E-tag antibodies is used to monitor protein expression. Otherwise, adding HRP-conjugated HIS-tag, S-tag, or E-tag antibodies is needed to activate the color reaction, which makes the procedure quite troublesome."

Supplementing the background information on this patent, NewsRx reporters also obtained the inventors' summary information for this patent: "The present invention provides an auto-developing and regularly-weighted protein molecular weight marker kit, which comprises: (a) a plurality of recombinant proteins having formula (I), (B).sub.m-A-(C).sub.n (I),

"wherein A is a polypeptide of SEQ ID NO: 1, B and C are independently any mutually identical or different polypeptides with molecular weight being about a multiple of 5, and m and n is independently 0 or any integer larger than 0; and (b) one or more solvents for stabilizing the recombinant proteins. The present invention also provides a method for preparing the auto-developing protein marker kit with regular molecular weight comprising: (a) constructing a plurality of nucleotide sequences encoding recombinant protein having formula (I) into DNA plasmids independently, and obtain a recombinant protein expressing vector, (B).sub.m-A-(C).sub.n (I),

"wherein A is a polypeptide of SEQ ID NO: 1, B and C are independently any mutually identical or different polypeptides with molecular weight being about a multiple of 5, and m and n is independently 0 or any integer larger than 0; (b) transforming the recombinant protein expressing vector into competent cells; selecting the competent cells carried the recombinant protein expressing vector; (d) administering the competent cell carried the recombinant protein expressing vector with inducer to induce expression of recombinant proteins; and (e) extracting recombinant proteins with different molecular weights independently, and mixing the plurality of recombinant proteins with one or more solvents for stabilizing recombinant proteins."

For the URL and additional information on this patent, see: Cheng, Tian-Lu; Cheng, Chiu-Min. Auto-Developing and Regularly-Weighted Protein Molecular Weight Marker Kit and Method for Preparing the Same. U.S. Patent Number 8791240, filed February 22, 2012, and published online on July 29, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8791240.PN.&OS=PN/8791240RS=PN/8791240

Keywords for this news article include: Antibodies, Peptides, Immunology, Amino Acids, Blood Proteins, Immunoglobulins, Recombinant Proteins, Kaohsiung Medical University.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Life Science Weekly


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