• Journal of Dairy Science and Biotechnology
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• v.23 no.1
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• pp.1-8
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• 2005

The purpose of this study was to demonstrate biochemical properties and antibacterial activity of lactoferrin(Lf) obtained from the colostrum of Korean native cow. Lactoferrin was isolated from the colostrum of Korean native cow by purification steps using batch extraction, ion exchange chromatography, gel filtration chromatography, affinity chromatography. Other whey protein components that is similar molecular weight and affinity to lactoferrin were gradually removed from crude Korean Native cow's lactoferrin during the purification steps. The molecular weight of the purified Korean native cow's Lf(K-Lf) was 81 kDa, the isoelectric point was 9, and the content of iron was 0.56mg/g, which is indicated that iron saturation of the K-Lf was 40.6%. Amino acid composition and a-helix content were different K-Lf from bovine Lf(B-Lf). Antibacterial activity of E. coli O111 by K-Lf was lower than that of B-Lf. A minimal inhibitory concentration(MIC) of K-Lf and B-Lf was 2.75mg/ml and 1.5mg/ml respectively.

• Journal of Life Science
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• v.14 no.4
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• pp.708-715
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• 2004

The lactate dehydrogenase (EC 1.1.1.27, LDH) in liver of Lempetra japonica was purified in buffer of affinity chromatography. The liver-specific $C_4$ isozyme of Gadus macrocephalus was purified by heat treatment, affinity chromatography, and DEAE-Sephacel chromatography. The liver-specific $C_4$ isozyme was eluted in a buffer containing NAD+ and was coeluted with $B_4$isozyme in plain buffer of affinity chromagraphy. Liver-specific $C_4$ isozyme in G. macrocephalus was the most thermostable, and$B_4$isozyme was more stable than $A_4$. The LDH in the fraction of pH 7.45 purified from the liver of L. iaponica by chromatofocusing was more inhibited by pyruvate than purified LDH. The optimum pH of the LDH isozyme in the liver of L. japonica was 7.5 and that of liver-specific$C_4$ isozyme was 8.5. The LDH in liver of L. japonica made complexes more with antibody against Coreoperca herzi$A_4$ and liver-specific $C_4$ than with that against eye-specific $C_4$. Therefore, the structure of the LDH in liver of L. japonica might be similarly evolved to that of subunit A and liver-specific $C_4$ isozyme in liver tissue of G. macrocephalus. The evolution rate of subunit C is faster than that of subunit A. LDH in liver of L. japonica has not one isozyme but isozymes and it was also found out to have not only subunit A and B but also subunit C.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.316-322
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• 1998

An ${\alpha}$-D-galactosidase (${\alpha}$-D-galactoside galactohydrolase, EC 3. 2. 1. 22) from sunflower seed was purified by affinity chromatography using N-$\varepsilon$-aminocaproyl-${\alpha}$-D-galactopyranosylamine coupled to sepharose and its properties were examined. The specific activity of the purified enzyme, tested with p-nitrophenyl-${\alpha}$-D-galactopyranoside as substrate, was 291.66 units/mg protein, representing an 115-folds purification of the original crude extract. The final preparation obtained from by Sephadex G-25 chromatography showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 42,000 by SDS-polyacrylamide gel electrophoresis. The purified galactosidase showed maximum activity at pH 4.5 and 55$^{\circ}C$, and was stable in the pH and temperature ranges of 4.0 to 5.0 and 30 to 55$^{\circ}C$, respectively. The enzyme activity was inhibited by Ag$\^$2+/, Hg$\^$2+/ and Co$\^$2+/. The enzyme activity was not affected considerably by treatment with other metal compounds. The enzyme liberated galactose from melibiose, raffinose, copra galactomannan, guar gum and locust bean gum by TLC, and also the hydrolysis rate of substrate was compared by HPLC.

• Archives of Pharmacal Research
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• v.20 no.4
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• pp.306-312
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• 1997

We attempted to isolate and characterize the lectins from stem and leaves of Korean mistletoe (Viscum album var. coloratum) by affinity chromatography. Lectin I was isolated only from stem. Lectin II was not isolated from Korean mistletoe, whereas lectin III was isolated from the stem and leaves. The hemagglutinating activity of lectin I was 16HU and inhibited by D-galactose, lactose, and N-acetyl-D-galactosamine. The lectin I has molecular weight of 60, 000D being composed of two basic subunits with molecular weights of 32, 000D and 28, 000D which are linked by a disufide bond. The lectin III from stem has molecular weight of 66, 000D being two basic subunits which have molecular weights of 34, 000D and 29, 000D and are linked by a disufide bond. The activity of lectin I was stable at the pH range of 4.00-8.50 and at a wide range of temperature (0-42.deg. C). The lectin I showed more potent mitogenic activity to murine lymphocytes than concanavalin A.

• KSBB Journal
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• v.14 no.3
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• pp.322-327
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• 1999

The cholesterol oxidase(EC.1.1.3.6) produced from Streptomyces sp. No.4 which isolated from soil was purified and investigated for the enzymatic properties. The enzyme was purified specifically by cholesterol affinity column chromatography with a yield of 28.3%. The purified enzyme showed a single polypeptide on SDS-PAGE and the molecular weight was estimated to be 60,000 daltons. The enzyme activity was strongly inhibited by metal ions such as $HgCl_2$ and $CuSO_4$. Dithiothreitol and mercaptoethanol inhibited the enzyme activity at concentration of 1mM. The Michaelis constant(Km) for cholesterol was found to be 1.38mM by Lineweaver-Burk plot analysis. Amino acid analysis showed that the enzyme protein was composed of 416 amino acid residues including 52moles of glycine and 19moles of tryptophane.

• Membrane Journal
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• v.16 no.1
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• pp.39-50
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• 2006

Porous chitosan and chitin membranes were prepared by using silica particles as porogen. Membrane preparation was achieved via the following three steps: (1) chitosan film formation by casting an chitosan solution containing silica particles, (2) preparation of porous chitosan membrane by dissolving the silica particles by immersing the film into an alkaline solution and (3) preparation of porous chitin membrane by acetylation of chitosan membrane with acetic anhydride. The optimum preparation conditions which could provide a chitosan and chitin membranes with good mechanical strength and adequate pure water flux were determined. To allow protein affinity, a reactive dye (Cibacron Blue 3GA) was immobilized on porous chitosan membrane. Binding capacities of affinity chitosan and chitin membranes for protein and enzyme were determined by the batch adsorption experiments of BSA protein and lysozyme enzyme. The maximum binding capacity of affinity chitosan membrane for BSA protein is about 22 mg/mL, and that of affinity chitin membrane for lysozyme enzyme is about 26 mg/mL. Those binding capacities are about $several{\sim}several$ tens times larger than those of chitosan and chitin-based hydrogel beads. Those results suggest that the porous chitosan and chitin membranes are suitable in affinity filtration chromatography for large scale separation of proteins.

• Biomedical Science Letters
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• v.18 no.2
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• pp.96-103
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• 2012

Kv 4.2 ion channel protein has an ability to open at subthreshold membrane potentials and to recover quickly from inactivation. That is very important for neuronal signal transmission in vertebrate brain. In order to purify Kv 4.2 protein, the novel purification methods were experimented. The purification procedure utilized chromatography on DE-52 ion exchange column and affinity chromatography on a WGA-Sepharose 4B, and Kv 4.2 affinity column chromatography. It was found that 0.5% (wt./vol.) Triton X-100 detergent in lysis buffer worked well for Kv 4.2 protein solubilization from rat brain membrane. Protein quantitative determination was conducted by BCA method at 562 nm for each purification step to avoid determination interference of protein at 280 nm by detergent. The confirmation of Kv 4.2 existence and amount is performed using by SDS-PAGE/immunoblotting or 96-well dot blotting. The Kv 4.2 without interacting protein that contains carbohydrate, was purified from novel biochemical 3-steps purification method for further research.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.201-204
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• 2003

Glycopeptide antibiotics, teicoplanin was purified from a mutant strain of Actinoplanes teichomyceticus ATCC31121, A. teichomyceticus MSL2211. We developed a simple procedure to separate and purify the teicoplanin from the fermentation broth. Teicoplanin was purified by two-step purification system, hydrophobic adsorption and sugar affinity chromatography in combination with HPLC analysis based on the properties of hydrophobic acyl chain and sugar moiety in teicoplanin. Teicoplanin was separated from the culture broth by Diaion HP-20 and further purified by concanavalin A affinity column chromatography. As an adsorbent resin, Diaion HP-20 in broth eliminated toxic effects on growth, reduced feedback repression of teicoplanin production, and assisted In rapid recovery of teicoplanin. The teicoplanin displayed the final yield of 80% and 95% of purity.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.619-622
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• 2000

For the production of $B^{30}-homoserine$ human insulin precursor, four types of fusion peptides LacZ, MBP, GST, and His-tagged sequence were studied in this work. Recombinant E. coli JM 103 and E. coli JM 109 containing fusion peptides were cultivated at $37^{\circ}C$ for 1hr, and gene expression was occurred when 0.5mM of isopropyl-D-thiogalactoside(IPTG) was added to the culture broth, and followed by longer than 4hr fermentation respectively. DEAE-Sphacel and gel filtration chromatography, amylose and glutathione-Sepharose 4B affinity chromatography, and nickel-affinity chromatography system were employed as purification of $B^{30}-homoserine$ human insulin precursor. Recovery yields of His-tagged, LacZ, GST, and MBP fused $B^{30}-homoserine$ human insulin precursor resulted in 47%, 20%, 20%, and 18%, respectively.

• Food Science of Animal Resources
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• v.20 no.2
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• pp.125-132
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• 2000

Lactoferrin was isolated from the colostrum of Korean native cow by using several purification steps such as batch extraction, ion exchange chromatography, gel filtration chromatography and affinity chromatography. Other whey protein components that having similar molecular weight and affinity to lactoferrin were gradually removed from crude Korean native cow's lactoferrin during the purification steps. The amount of lactoferrin collected from a liter of Korean native cow's colostrum was 65mg and the recovery rate was 29.4%. The molecular weight of the purified Korean native cow's lactoferrin was estimated approximately 81,000dalton.