• 한국식품영양과학회지
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• 제40권2호
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• pp.327-333
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• 2011

Alcalase, protamex 및 neutrase 효소처리가 청국장의 펩타이드 및 항산화 활성 증가에 미치는 영향을 동일한 조건으로 효소 처리한 대두분말과 비교하였다. 효소 20, 100 및 500 mAU를 $50^{\circ}C$에서 120분간 처리한 결과 청국장과 대두분말 모두에서 alcalase 및 protamex에 의한 펩타이드 생성이 neutrase보다 높게 나타났다. 항산화 활성은 청국장의 경우 alcalase 처리에 의해 DPPH, ABTS 및 hydroxyl radical 소거활성이 효소처리를 하지 않은 대조구와 비교하여 시료량에 따라 각각 37~57%, 59~106% 및 67~83%, protamex 처리에 의해 35~50%, 56~74% 및 52~75% 통계적으로 유의하게 증가하였다. 대두분말을 효소 처리한 시료에서도 유사한 결과를 보여 alcalase 처리에 의해 DPPH, ABTS 및 hydroxyl radical 소거활성이 각각 37~55%, 51~99% 및 67~83%, protamex 처리에 의해 36~44%, 44~66% 및 51~65% 증가하였다. 그러나 두 시료 모두에서 neutrase 처리에 의한 항산화 활성의 유의적 증가는 없었다. 이상의 결과는 alcalase와 protamex가 청국장에 특이적이지는 않으나 펩타이드 생성 및 항산화 활성 증가에 효율적임을 보여주고 있다.

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.132-137
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• 2010

The skc gene encoding streptokinase (SK) with a molecular mass of approximately 47.4 kDa was cloned from Streptococcus equisimilis ATCC 9542 and heterologously overexpressed in Streptomyces lividans TK24 and E. coli using various strong promoters. When the promoter for sprT [Streptomyces griseus trypsin (SGT)] was used in the host S. lividans TK24, a 47.4-kDa protein was detected along with a smaller hydrolyzed protein (44 kDa), suggesting that posttranslational hydrolysis had occurred as has been reported in other expression systems. The casein/plasminogen plate assay revealed that the plasmid construct containing the SGT signal peptide was superior to that containing the SK signal peptide in terms of SK production. Maximal production of SK was calculated to be about 0.25 unit/ml of culture broth, a value that was five times higher than that obtained with other expression systems using ermE and tipA promoters in the same host. When the skc gene was expressed in E. coli BL21(${\Delta}DE3$)pLys under the control of the T7 promoter, a relatively large amount of SK was expressed in soluble form without hydrolysis. SK activity in E. coli/pET28a-$T7_pSK_m$ was more than 2 units/ml of culture broth, even though about half of the expressed protein formed an inactive inclusion body.

• 한국미생물·생명공학회지
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• 제34권2호
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• pp.115-120
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• 2006

천연 단백질인 실크를 가수분해하여, 건강기능성 식품 등에 다양하게 활용될 수 있는 가용성 실크 펩타이드를 생산하는 효소공학적 연구를 수행하였다. 효소는 Bacillus, Aspergillus, 파파야, 파인애플 등으로부터 유래하는 10종의 프로티아제를 사용하였으며,가수분해 효율을 높이기 위하여 생 실크를 $CaCl_2$- 에탄올 공용액에 녹인 가용화된 실크를 제조하였고, 이를 상온 중성의 조건에서 50시간 동안 투석하여 효소반응을 위한 기질로 사용하였다. 효소반응은 37, pH 7.0에서 수행하였으며, 파인애플 유래 프로티아제인 Bromelain과 Bacillus유래 효소인 Alcalase가 실크의 가수분해에 적합한 것으로 확인되었다. 특히 파인애플 유래의 Bromelain은 가수분해 도중 불용성 침전물의 형성으로 인한 생산 수율의 감소가 가장 적어 가용성 실크 펩타이드의 제조에 적합하였고, 분자량 분포에 있어서도 보다 다양한 것으로 확인되었다.

• 한국축산식품학회지
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• 제30권6호
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• pp.923-929
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• 2010

Colostral whey prepared from colostrum (pooled from first six post-partum milkings) was heated for 10 min at $100^{\circ}C$ Heated colostral whey was incubated with 1% enzymes (protein equivalent basis) for 15, 30, 60, 90, and 120 min at $50^{\circ}C$. Papain, pepsin, trypsin, and alcalase produced different degrees of hydrolysis (DH), 10.66%, 12.42%, 10.83%, and 25.31%, respectively, at an incubation time of 120 min. The SDS-PAGE reveals that significant amounts of bovine serum albumin (BSA), ${\beta}$-lactoglobulin (${\beta}$-LG), and ${\alpha}$-lactalbumin (${\alpha}$-LA) survived papain digestion. In contrast, pepsin completely removed BSA but not ${\beta}$-LG present in heated colostral whey. Alcalase completely eliminated BSA, ${\beta}$-LG, and ${\alpha}$-LA. This differential hydrolysis was confirmed by reversed-phase HPLC analysis. Using ion-exchange chromatography, fraction-1 (F-1) was obtained from alcalase hydrolysate at a NaCl gradient concentration of 0.25 M. Reversed-phase HPLC chromatograms of alcalase F-1 showed numerous small peaks, which probably indicate that a variety of new peptides were produced. Iron content of alcalase F-1 was 28.94 ppm, which was the highest among all enzyme fractions, whereas iron content of colostral whey was 36.56 ppm. Main amino acids contained in alcalase F-1 were Thr (15.45%), Glu (14.12%), and Ser (10.39%). Therefore, alcalase can be used to generate good iron-binding peptides in heated colostral whey, and the resulting iron-binding peptides could be suitable as a value-added food ingredient for food supplements.

• 한국축산식품학회지
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• 제44권3호
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• pp.723-737
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• 2024

Yeast protein can be a nutritionally suitable auxiliary protein source in livestock food. The breakdown of proteins and thereby generating high-quality peptide, typically provides nutritional benefits. Enzyme hydrolysis has been effectively uesed to generate peptides; however, studies on the potential applications of different types of enzymes to produce yeast protein hydrolysates remain limited. This study investigated the effects of endo- (alcalase and neutrase) and exotype (flavourzyme and prozyme 2000P) enzyme treatments on yeast protein. Endotype enzymes facilitate a higher hydrolysis efficiency in yeast proteins than exotype enzymes. The highest degree of hydrolysis was observed for the protein treated with neutrase, which was followed by alcalase, prozyme 2000P, and flavourzyme. Furthermore, endotype enzyme treated proteins exhibited higher solubility than their exotype counterparts. Notably, the more uniform particle size distribution was observed in endotype treated yeast protein. Moreover, compared with the original yeast protein, the enzymatic protein hydrolysates possessed a higher content of β-sheets structures, indicating their higher structural stability. Regardless of enzyme type, enzyme treated protein possessed a higher total free amino acid content including essential amino acids. Therefore, this study provides significant insights into the production of protein hydrolysates as an alternative protein material.

• 한국수산과학회지
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• 제31권6호
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• pp.875-881
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• 1998

젓갈 및 자건품으로 소비량이 많은 멸치의 기능특성해석 및 기능성 조미 소재 제조의 일환으로 단백질 분해효소에 의한 멸치 육단백질 가수분해물의 peptide-nitrogen 생성량과 ACE 저해작용을 검토하였다. 소화효소와 식품공업용 단백질분해효소를 이용한 탈지 멸치육 가수분해물의 $50\%$ ethanol 가용성 peptide-nitrogen 생성량은 반응 8시간을 전후로 하여 거의 일정수준에 도달하였고, ACE 저해효과 역시 높게 나타났다. 따라서, 가수분해 8시간째의 각 효소 가수분해물의 peptide-nitrogen의 함량과 ACE 저해효과를 검토한 결과, 소화효소의 경우, $\alpha$-chymotrypsin으로 가수분해시켰을 때, $50\%$ ethanol 가용성 peptide-nitrogen의 생성량과 ACE 저해효과가 높은 것으로 나타났다 또한, 식품공업용 단백질분해 효소를 사용한 경우는 Alcalase 0.6L를 사용하였을 때가 $50\%$ ethanol 가용성 peptide-nitrogen의 생성량 및 ACE 저해효과가 가장 우수하였고, Protamex에 의해서는 $50\%$ ethanol 가용성 peptide-nitrogen의 생성량은 적었지만, ACE 저해효과는 높게 나타났다. ACE 저해효과가 우수한 멸치육 효소 가수분해물의 $50\%$ ethanol 가용성 획분의 아미노산 조성은 대부분의 가수분해물에서 glutamic acid의 함량이 가장 많았고, 그 다음으로 aspartic acid. cysteine 및 leucine의 순이었다.

• 한국식품과학회지
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• 제27권5호
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• pp.794-798
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• 1995

식품단백질의 효율적인 이용을 위하여 neutrase에 의한 glutamine과 asparagine 잔기의 탈아미드화에 관한 연구를 행하였다. Neutrase에 의한 BSA의 최적반응 조건은 $20^{\circ}C$, pH 10에서 3시간 반응시켰을 때로, 이때 BSA는 24%가 탈아미드화되었고. 동시에 2.9%가 가수분해되었다. 또한 pronase, bromelain, ficin 보다는 neutrase에 의한 BSA의 탈아미드화율이 높은 것으로 나타났다. 최적 탈아미드화 조건에서 neutrase에 의한 egg albumin, 분리콩단백 및 casein의 경우 탈아미드화에 수반하여 펩티드결합의 분해가 비교적 높게 관찰되었다.

• Journal of Microbiology and Biotechnology
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• 제2권1호
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• pp.56-65
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• 1992

The complete nucleotide sequence of the Bacillus circulans F-2 RSDA gene, coding for raw starch digesting a-amylase (RSDA), has been determined. The RSDA structure gene consists of an open reading frame of 2508 bp. Six bp upstream of the translational start codon of the RSDA is a typical gram-positive Shine-Dalgarno sequence and the RSDA encodes a preprotein of 836 amino acids with an Mr of 96, 727. The gene was expressed from its own regulatory region in E. coli and two putative consensus promoter sequences were identified upstream of a ribosome binding site and an ATG start codon. Confirmation of the nucleotide sequence was obtained and the signal peptide cleavage site was identified by comparing the predicted amino acid sequence with that derived by N-terminal analysis of the purified RSDA. The deduced N-terminal region of the RSDA conforms to the general pattern for the signal peptides of secreted prokaryotic proteins. The complete amino acid sequence was deduced and homology with other enzymes was compared. The results suggested that the Thr-Ser-rich hinge region and the non-catalytic domain are necessary for efficient adsorption onto raw substrates, and the catalytic domain (60 kDa) is necessary for the hydrolysis of substrates, as suggested in previous studies (8, 9).

• Journal of Dairy Science and Biotechnology
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• 제39권1호
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• pp.36-50
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• 2021

This study aimed to evaluate the biological potential of functional food, i.e., specific peptides obtained from the hydrolysis of milk protein, by assessing their antioxidant and antibacterial properties. For the preparation of casein hydrolysates, commercial enzymes were added to 10% casein solution in a 1:200 (w/v) ratio, and samples were collected each hour. Based on the assessment of the degree of hydrolysis (DH) of casein hydrolysates, it was observed that the concentration of all enzymatic hydrolysates increased rapidly from 30 to 40 minutes. However, no change was observed in their concentrations after 150 minutes. Protamex® and Neutrase® exhibited the highest DH when compared to other enzymes. Furthermore, SDS-PAGE was performed for analyzing the proteolytic pattern of each enzyme, except for Flavourzyme®, and peptides in the size range of 20-25 kDa were identified. Subsequently, peptides produced by two enzymes were isolated using a preparative liquid chromatography system. Overall, NF3, NF4, PF5, and PF6 showed higher antioxidant potential than other peptide fractions. Moreover, NF7 and PF3 exhibited the highest antibacterial activity. In this study, we evaluated the biological potential of novel casein-derived peptides that may find application in the food and healthcare industry.

• Applied Biological Chemistry
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• 제13권1호
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• pp.65-72
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• 1970

Bence Jones 단백질중(蛋白質中) ${\lambda}$형(型)의 N-말단(末端) 및 그 주변(周邊)의 아미노산배열(酸配列)을 결정(決定)하기 위하여 본(本) 실험(實輸)이 시도(試圖)되었던바 그 결과(結果)는 다음과 같다. 1) Bence Jones 단백질(蛋白質)을 Pronase와 Chymotrypsin으로 분해(分解)하여 얻은 Peptide중에서 Im Pr-M 및 Im Ch-M와 Ik Ch-M을 Dowex $50{\times}2$ column $1{\times}20$cm)와 Dowex $1{\times}2$ column $(0.9{\times}50{\;}cm)$을 사용(使用)하여 분리(分離)하였다. 2) ${\lambda}$형(型) Bence Jones단백질(蛋白質)의 N-말단(末端)은pyrroglutamic acid로 되어 있음을 alkali반응(反應)과 고압여지전기영동법(高壓濾紙電氣泳動法)으로 확인(確認)하였다. 3) 농염산(濃鹽酸)(12N) 반응(反應)($27^{\circ}C$, 15시간(時間))을 이용(利用)하며 Peptide중(中)의 Serine부(部)를 선택적(選擇的)으로 절단(切斷)할 수 있었다. 4) 이들 Peptide의 아미노배열순서(配列順序)는 Edman의 PTC법(法)과 소거법(消去法) 및 CarboBypeptidase A를 사용(使用)하여 결정(決定)하였다. 5) 분리(分離)한 Peptide의 아미노산배열순서(酸配列順序)는 다음과 같았다. $Im\;Ch-M\;PCA{\cdot}Ser{\cdot}Val{\cdot}Leu$ $Ik\;Ch-M\;PCA{\cdot}Ser{\cdot}Ala{\cdot}Leu1$