• Journal of Microbiology and Biotechnology
• /
• 제24권3호
• /
• pp.337-345
• /
• 2014

Pichia pastoris is one of the most widely used expression systems for the secretory expression of recombinant proteins. The secretory expression in P. pastoris usually makes use of the prepro $MAT{\alpha}$ sequence from Saccharomyces cerevisiae, which has a dibasic amino acid cleavage site at the end of the signal sequence. This is efficiently processed by Kex2 protease, resulting in the secretion of high levels of proteins to the medium. However, the proteins that are having the internal accessible dibasic amino acids such as KR and RR in the coding region cannot be expressed using this signal sequence, as the protein will be fragmented. We have identified a new signal sequence of 18 amino acids from a P. pastoris protein that can secrete proteins to the medium efficiently. The PMT1-gene-inactivated P. pastoris strain secretes a ~30 kDa protein into the extracellular medium. We have identified this protein by determining its N-terminal amino acid sequence. The protein secreted has four DDDK concatameric internal repeats. This protein was not secreted in the wild-type P. pastoris under normal culture conditions. We show that the 18-amino-acid signal peptide at the N-terminal of this protein is useful for secretion of heterologous proteins in Pichia.

• 농업과학연구
• /
• 제50권2호
• /
• pp.281-294
• /
• 2023

As a byproduct obtained from cheese manufacture, whey protein was developed as a functional food that contains multi-functional proteins. In this study, the biochemical activity of fermented milk prepared by fortifying whey protein with excellent physiological activity was investigated. Immunoglobulin (IgG) content was higher in 10% fortified whey protein fermented milk than in the control. The viable cell counts were 20% higher in the fermented milk with 10% fortified whey protein than in the control group. The antibacterial effect of 10% fortified whey protein fermented milk compared to the control group was shown to be effective against four pathogenic microorganisms, Escherichia coli (KCTC1039), Pseudomonas aeruginosa 530, Salmonela Typhimurium (KCTC3216), and Staphylococcus aureus (KCTC1621). The antioxidant effect by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities wasincreased two-fold in 10% fortified whey protein fermented milk compared to the control. The 10% fortified whey protein fermented milk inhibited the expression of the inflammatory cytokines (interleukin [IL]-6, tumor necrosis factor [TNF]-α, and induced nitric oxide synthase [iNOS]) in a concentration-dependent manner. In a piglets feeding test, the weight gain with 10% fortified whey protein fermented milk was increased by 18% compared to the control group, and no diarrhea symptoms appeared. Our results clearly demonstrated that 10% fortified whey protein fermented milk could be a useful functional ingredient for improving health.

• Journal of Nutrition and Health
• /
• 제22권6호
• /
• pp.516-530
• /
• 1989

A 44-day metabolic study was conducted to compare the effects of soy protein and meat protein on N, Ca, P, and Mg metabolism in young Korean males. Meat protein diet(MPD) and soy protin diet(SPD) were provided for 3 weeks each. For MPD, meat protein Supplied 50.3% of total protein and mean daily suplies of Ca, P, and Mg were 33.28mg, 1013.01mg, 226.81mg respectively. For SPD, soy protein supplied 51.8% of total protein and mean contents of Ca, P and Mg were 737.86mg, 1261.76mg, and 451.3mg. Mean daily fecal and urinary excretions of Ca were 350.6mg and 113.3mg for MPD and 515.0mg and 118.3mg for SPD. Apparent absorption rates in MPD and SPD were 4.2mg in MPD and 700.4mg and 475.1mg SPD. Apparent absorption rates were 65.6% in MPD and 44.5% in SPD(p<0.01). For Mg, fecal and urinary excretions were 144.8mg and 81.2mg in MPD and 292.4mg and 65.5mg in SPD. Apparent absorption rates were 37.5% in MPD and 35.2% in SPD. The correlations between urinary Ca, P, and their balance were significant (p<0.001) in MPD, but not in SPD. Urinary Ca was significantly correlated with urinary N, P, Mg(p<0.001) in MPD, but not in SPD. From these results, meat protein seems to increase the excretions of major minerals compared to soy protein.

• 한국가정과학회지
• /
• 제7권1호
• /
• pp.43-50
• /
• 2004

The purpose of this study is to reach silk protein added in differing amounts to Jeolpyon, Korean traditional rice cake, using rice powder as its primary material, estimation of the micro organism quality, physicochemical property, sensory evaluation and the property of storage period (20${pm} 5 ^{\circ}C$). In the physicochemical property, the content of proximate composition of rice powder was measured as 38.11% of moisture, 56.62% of total sugar, 5.11% of crude protein, 0.52% of crude lipid, 0.25% of ash. And the raw material of silk protein was measured as 6.61% of moisture, 91.22% of crude protein, 6.41% of crude lipid and 0.75% of ash. The pH of raw material for rice powder and silk protein Jeolpyon showed mild acidity as 6.41 and 6.23, respectively. In rice powder and silk protein, total free sugar contents was 0.89% and 0.02%, and total amino acids contents was 4.28% and 52.21 %, respectively. For sensory evaluation. color, taste, softness and adhesiveness were significantly acceptable in control and adding 1 % silk protein. Control and samples added 1$\sim$3% silk protein had high sensory score color in overall acceptance. In conclusion. Jeolpyon can be manufactured with nutritious Jeolpyon by adding silk protein.

• 한국축산식품학회지
• /
• 제23권1호
• /
• pp.63-69
• /
• 2003

본 연구는 단백질분해효소로 whey protein을 가수분해하여 얻은 가수분해물의 용해도와 유화특성의 변화를 측정하기 위해 실시하였다. Whey protein concentrates를 porcine trypsin(E : S=1 ; 3,000)으로 pH 8.0, 37$^{\circ}C$에서 6시간 동안 가수분해한 whey protein 가수분해물의 유화활성은 분해 4시간째에 가장 높게 나타났으며, 이 때 가수분해도는 5.50%이었다. whey protein의 효소가수분해로 whey protein 중의 $\alpha$-lactalbumin은 분해가 잘 일어나지 않으나 $\beta$-lactoglobulin은 분해 초기부터 급속히 분해되며 유화력 상승에 관여하는 여 러개의 저분자량 peptide를 생성하였다. 가수분해물의 용해도는 가수분해시간이 지남에 따라 증가세를 보이다가 5시간부터 조금씩 감소 추세를 보였으며, pH에 따라서는 등전점 부근인 pH4~5에서 용해도가 가장 낮았으나 가수분해시간이 증가함에 따라 이 부근의 용해도가 현저히 증가하였으며 pH 6이상에서는 pH가 증가함에 따라 용해도도 증가하였다. 유화활성은 용해도의 결과와 거의 비슷한 결과를 나타내었다. 유화 안정성은 분해시간이 지남에 따라 조금씩 증가함을 보여주었으나, 가수분해 4시간부터 pH 8 이상의 PH에서 급격한 증자를 나타내었다.

• 생명과학회지
• /
• 제18권3호
• /
• pp.318-322
• /
• 2008

단백질 상호작용 관련 데이터들이 기하급수적으로 증가하고 있는데 그러한 데이터들을 수동으로 갱신하고 관리하는 작업은 엄청나게 많은 시간과 노력을 요구한다. 뿐만 아니라 개발자가 아닌 비전문가인 생물학자들이 시스템 구성 데이터베이스들을 갱신하고 관리하며 분석 시스템을 운영한다는 것은 현실적으로 거의 불가능하다. 이러한 측면에서 단백질 상호작용 정보를 이용한 효율적인 단백질 기능분석 시스템인 WASPIFA에 대해 자동적으로 데이터를 갱신하고 관리할 수 있는 시스템을 설계하고 개발하였다. WASPIFA 시스템은 단백질의 상호작용 관련 데이터들을 통합하여 사용자가 편리하게 데이터를 검색할 수 있으며 단백질 상호작용에 관련된 정보 즉, 기능 및 주석 정보, 도메인 정보, 도메인 간의 상호 작용 정보 등을 제공해 주는 유용한 단백질 기능분석 시스템이다.

• Radiation Oncology Journal
• /
• 제38권2호
• /
• pp.129-137
• /
• 2020

Purpose: To identify the clinical usefulness of serum M protein and to establish a rationale for regular follow-up with serum protein electrophoresis in solitary plasmacytoma. Materials and Methods: Sixty-nine patients with solitary plasmacytoma and solitary plasmacytoma with minimal marrow involvement according to the International Myeloma Working Group criteria were retrospectively reviewed. Results: At a median follow-up of 6.2 years, 5-year local control (LC), 5-year multiple myeloma-free survival (MMFS), 5-year failure-free survival (FFS), and 5-year overall survival (OS) were 82.6%, 44.1%, 41.8%, and 85.1%, respectively. Among the patients whose initial serum M protein was present or not evaluated, 37.3% of patients showed disappearance of serum M protein after various treatment. MMFS of these patients were comparable to non-secretory plasmacytoma with undetectable levels of M protein, and significantly better than patients with persistent M protein. Increase of serum M protein ≥0.1 g/dL was most predictive of treatment failure with area under the curve of 0.731. Conclusion: Patients who eventually showed persistence of serum M protein after treatment showed worse MMFS and FFS compared to those whose serum M protein disappeared or who had initially non-secretory disease. The increase of serum M protein level ≥0.1 g/dL from current nadir was predictive of treatment failure. Therefore, regular follow-up with serum M protein is highly recommended especially unless the patient had initially non-secretory disease.

• BMB Reports
• /
• 제33권6호
• /
• pp.427-439
• /
• 2000

The activity of the phagocyte respiratory burst oxidase is regulated by complex and dynamic alterations in protein-protein interactions that result in the rapid assembly of an active multicomponent NADPH oxidase enzyme on the plasma membrane. While the enzymatic activity has been studied for the past 20 years, the past decade has seen remarkable progress in our understanding of the enzyme and its activation at the molecular level. This article describes the current state of knowledge, and proposes a model for the mechanism by which protein-protein interactions regulate enzyme activity in this system.

• Bioinformatics and Biosystems
• /
• 제1권2호
• /
• pp.128-133
• /
• 2006

This paper compares domain combination based protein-protein interaction prediction method with domain based protein-protein interaction method. The prediction accuracy and reliability of the methods are compared using the same prediction technique and interaction data. According to the comparison, domain combination based prediction method has showed superior prediction accuracy to domain based prediction method for protein pairs with fully overlapped domains with protein pairs in learning sets. When we consider that domain combination based method has the effects of assigning a weight to each domain interaction, it implies that we can improve the prediction accuracies of currently available domain or domain combination based protein interaction prediction methods further by developing more advanced weight assignment techniques. Several significant facts revealed from the comparative studies are also described in this paper.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2001년도 추계학술발표대회
• /
• pp.719-722
• /
• 2001

Silk proteins from Nephila clavipes are fibrous proteins containing repetitive sequences with both crystalline and amorphous domains. In order to obtain high-level production of silk protein, the synthetic genes had 16 contiguous units of the consensus repeat sequence of the silk protein were expressed in Escherichia coli BL21(DE3) under the strong inducible T7 promoter. For production of recombinant silk protein in large amounts, pH-stat fed-batch cultures were carried out. The recombinant silk protein was produced as soluble forms in E. coli, and the recombinant silk protein content was as high as 11% of the total protein. When cells were induced at $OD_{600}$ of 60, the amount of silk protein produced was 6.49 g/L. After simple purification steps, 9.2 mg of silk protein that was more than 80% pure was obtained from a 50 mL culture, and the recovery yield was 26.3%.