• 한국유가공학회:학술대회논문집
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• 2002.04a
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• pp.37-42
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• 2002

Lactoferrin is an iron-binding glycoprotein and its bacteriostatic and bactericidal effects on Gram-positive and Gram-negative bacteria have been well-known. However, certain kind of lactic acid bacteria are resistant against its antibacterial effects. Moreover, it is reported that lactoferrin promotes the growth of bifidobacteria by in vitro and in vivo experiments. In this experiment, lactoferrin-binding protein was found both in the membrane and cytosolic franctions of Bifidobacterium. Bifidobacterium was grown in anaerobic conditions in MRS broth containing cysteine, gathered by centrifugation and processed by sonication. The lactoferrin-binding proteins on the PVDF-membrane transferred after SDS-PAGE were detected by far-western method using biotinylated lactoferrin and streptavidin-labeled horse radish peroxidase. Observation in growth effects of lactoferrin on Bifidobacterium suggested that there is a relation between the presence of lactoferrin-binding proteins on the cells and their growth.

• BMB Reports
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• v.34 no.2
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• pp.102-108
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• 2001

A time-dependent folding process was used to determine whether or not protein disulfide isomerase (PDI) plays an important role in the maturation of nascent lactoferrin polypeptides. Interaction between lactoferrin and PDI was analyzed according to the co-immunoprecipitation of the two proteins. The results indicate that lactoferrin folding requires a significant interaction with PDI and its binding is relatively brief compared to other nascent polypeptides. The amount of lactoferrin interacting with PDI increases up to half a minute and sharply decreases beyond this time point. During the refolding process that follows reduction by DTT, lactoferrin polypeptides heavily interact with PDI and the interaction period was extended compared to the normal folding process. In terms of the temperature effect on PDI-lactoferrin interaction, PDI binds to lactoferrin polypeptides longer at a lower temperature (here, $25^{\circ}C$) than $37^{\circ}C$. The lactoferrin-PDI interaction was also studied in vitro. According to the in vitro experiment data, PDI was still functional in cell lysates assisting lactoferrin folding into the mature form. PDI interacts with lactoferrin polypeptides for an extended period during the folding in vitro. During the refolding process in vitro, intermolecular aggregates and refolding oligomers matured into a functional form after PDI binds to the lactoferrin. These results suggest that PDI provides a prolonged chaperoning activity in the refolding processes and that there appears to be a greater requirement for PDI chaperone activity in the refolding of lactoferrin polypeptides.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.305-307
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• 2007

Lactoferrin-binding proteins (LBP) has not been well characterized in Streptococcus uberis isolated from milk of bovine mastitis and to date this protein is considered to be an important virulence factor in Streptococcal mastitis. To determine the more efficient extraction method of LBP from four S. uberis strains, we used two different extraction methods (mutanolysin and sodium dodecyl sulfate) in this study. Bacterial proteins extracted were electrophoresed by 10% polyacrylamide gels in the presence of sodium deodecyl sulfate and gels were transferred onto nitrocellulose membrane. Rabbit anti-bovine lactoferrin antibody and HRP-conjugated donkey anti-rabbit IgG antibody were used to detect LBP. This Western blotting analysis demonstrates that extraction method with SDS extracted 110 kDa and 112 kDa LBPs more efficiently compared to the mutanolysin extraction method.

• Journal of Dairy Science and Biotechnology
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• v.27 no.1
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• pp.19-28
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• 2009

Lactoferrin was first identified 60 years ago as a "red protein" in bovine milk. Lactoferrin, one of the transferrin family proteins, is an iron-binding glycoprotein found in milk and various mucosal secretions; it is also released from activated neutrophils. Human lactoferrin has a molecular weight of 82.4 kDa and is composed of 702 or 692 amino acid residues. Bovine lactoferrin has a molecular weight of 83.1 kDa and is composed of 689 amino acid residues. Both lactoferrin and transferrin have the ability to bind two $Fe^{3+}$ ions, together with two ${CO_3}^{2-}$ ions with extremely high affinity; these proteins also have the ability to release this iron at low pH levels. The polypeptide chain in lactoferrin is folded into two globular lobes, representing the N-terminal and C-terminal halves. Both lobes have similar folding and 40% sequence identity. This protein is capable of multiple functions as described in various review papers, including antimicrobial, antiviral, antiinflammatory, anticancer, antioxidant, and cell growth-promoting activities. Lactoferrin also exhibits immunomodulating effects and plays an active role in the regulation of myelopoiesis and the inhibition of bacterial translocation.

• Food Science of Animal Resources
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• v.25 no.2
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• pp.232-237
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• 2005

Lactoferrin is a member of the transferrin family of iron-binding glycoproteins. It is originally found in milk. In addition to its antibacterial and antiviral activities, lactoferrin has many other biological functions include anti-inflammatory properties, antitumor, cell growth-promoting activity as well as antioxidant effect In the present study, we report the production of recombinant bovine lactoferrin and lactoferrin N-lobe in the Rhodococcus erythropolis (R erythropolis) using pTip vector. The expression level was investigated in various range of temperature, and we could successfully expressed the bovine lactoferrin and lactoferrin N-lobe in R erythropolis at low temperature. The recombinant proteins were purified by Nickel-Nitrolotriacetic acid (Ni-NTA). The purified proteins were confirmed by SDS-PAGE and Western blot, which indicating that the recombinant proteins have a molecular weight of 80kDa and 43kDa for bovine lactoferrin and lactoferrin N-lobe, respectively.

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.38-44
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• 2002

Pneumococcal surfacce protein A (PspA) is an important virulence factor and an antigenically variable surface protein of the pneumococci. To purify the PspA from S. pneumoniae KNIH1156 , a clinical isolate (type 19F), we have taken advantage of the fact that PspA is released from the surface of pneumococci into the medium by growing in a CDM-ET medium and PspA is capable of binding human lactoferrin, the iron carrier protein. PspA of S. pneumoniae KNIH1156 was purified from culture supernatant by human lactoferrin (hLf) affinity chromatography. The purified PspA was confirmed with anti-PspA antiserum and also had the binding capacity to hLf specifically. To determine whether the purified PspA could elicit protection in mice against pneumococcal inflection, we immunized the mice with purified PspA and subsequently challenged with S. pneumoniae KNIH1156. Immunization with purified PspA protected mice from 500 times the $LD^{50}$ of S. pneumoniae KNIH1156. Therefore, it has been shown that purified PspA fromS. pneumoniae KNIH1156 (type 19F) is a protective immunogen.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.556-561
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• 2010

Lactoferrin is an 80-kDa iron-binding glycoprotein that is found in high concentrations in human milk. Human lactoferrin (hLF) has several beneficial biological activities including immune system modulation and antimicrobial activity. In the present study, we devolved a method of hLF expression through introducing the hLF gene construct into Oriza sativa cv. Nakdong using the Agrobacterium-mediated transformation system. The expression of the hLF gene under the control of the rice glutelin promoter was detected in the seeds of transgenic rice plants. Transformed rice plants were selected on media containing herbicide(DL-phosphinothricin) and the integration of hLF cDNA was confirmed by Southern blot analysis. The expression of the full length hLF protein from the grains of transgenic rice plants was verified by Western blot analysis. The lactoferrin expression levels in the transformed rice grains determined by enzyme-linked immunosorbant assay accounted for approximately 1.5% of total soluble protein. Taken together, these data indicate that rice grains expressing hLF can be directly incorporated into infant formula and baby food.

• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.37-42
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• 2007

Lactoferrin, an ion-binding 80-kDa glycoprotein, has been suggested to have many biologic activities, such as facilitating ion absorption and having antimicrobial and anti-inflammatory effects. Several of these activities are likely to only be facilitated by human lactoferrin because they depend on the binding of human lactoferrin to specific receptor. To produce recombinant human lactoferrin to animal foods using transgenic silkworm, Bombyx mori L, we have cloned and sequenced the cDNA encoding for a human lactoferrin (HLf) from the mRNA in mammary tumor line (GI-101). As a result, the 2.5-kb fragment of HLf gene was cloned with pGEM-T vector and then this fragment was sequenced. In the nucleotide sequence analysis, single open reading frame of the 2,136-bp encoding for a polypeptide of 712 amino acid residues was detected. On the other hand, we constructed a recombinant plasmid(pPT-HLf), containing human lactoferrin gene for germ line transformation of the silkworm using a piggyBac transposon-derived vector. A nonautonomous helper plasmid encodes the piggyBac transposase. Approximately 6.7% of individuals in the G0 silkworms expressed green fluorescent protein (GFP). PCR analyses of GFP-positive silkworms (G0 and G1) revealed that independent insertions occurred frequently. Furthermore, Western blot analysis showed that the recombinant HLf expressed in hemolymph has the same molecular weight (80 kDa) as a native protein. On the basis of these experiments, expression of HLf in next generation of transgenic silkworm is now in process.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1877-1884
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• 2017

Mesenchymal stem cells (MSCs) have been suggested as a primary candidate for cell therapy applications because they have self-renewal and differentiation capabilities. Although they can be expanded in ex vivo system, clinical application of these cells is still limited because they survive poorly and undergo senescence or apoptosis when transplanted and exposed to environmental factors such as oxidative stress. Thus, reducing oxidative stress is expected to improve the efficacy of MSC therapy. The milk protein lactoferrin is a multifunctional iron-binding glycoprotein that plays various roles, including reduction of oxidative stress. Thus, we explored the effect of lactoferrin on oxidative stress-induced senescence and apoptosis of human MSCs (hMSCs). Measurement of reactive oxygen species (ROS) revealed that lactoferrin inhibited the production of hydrogen peroxide-induced intracellular ROS, suggesting lactoferrin as a good candidate as an antioxidant in hMSCs. Pretreatment of lactoferrin suppressed hydrogen peroxide-induced senescence of hMSCs. In addition, lactoferrin reduced hydrogen peroxide-induced apoptosis via inhibition of caspase-3 and Akt activation. These results demonstrate that lactoferrin can be a promising factor to protect hMSCs from oxidative stress-induced senescence and apoptosis, thus increasing the efficacy of MSC therapy.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.224-229
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• 2009

Human lactoferrin is an iron-binding glycoprotein with many biological activities, including the protection against microbial and virus infection and stimulation of the immune system. We introduced a human lactoferrin (hLf) cDNA under the control of 35S promoter into sweet potato by particle bombardment. Transgenic plants were regenerated via somatic embryogenesis. Transgenic plants were produced typical tuberous roots in soil. PCR, Southern and northern analyses confirmed that the hLf cDNA was incorporated into the plant genome and was properly expressed in plants. Western blot analysis showed that the 80 kDa full length hLf protein was produced in transgenic tuberous roots. Overall results indicated that sweet potato would be an excellent host to produce human therapeutic proteins.