• BMB Reports
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• 제37권1호
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• pp.59-74
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• 2004

The study of whole patterns of changes in protein expression and their modifications, or proteomics, presents both technological advances as well as formidable challenges to biological researchers. Nutrition research and the food sciences in general will be strongly influenced by the new knowledge generated by the proteomics approach. This review examines the different aspects of proteomics technologies, while emphasizing the value of consideration of "traditional" aspects of protein separation. These include the choice of the cell, the subcellular fraction, and the isolation and purification of the relevant protein fraction (if known) by protein chromatographic procedures. Qualitative and quantitative analyses of proteins and their peptides formed by proteolytic hydrolysis have been substantially enhanced by the development of mass spectrometry technologies in combination with nanoscale fluidics analysis. These are described, as are the pros and cons of each method in current use.

• Asian-Australasian Journal of Animal Sciences
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• 제7권4호
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• pp.531-535
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• 1994

APUD cells in the oviduct of the sheep at standing estrus were localized as paraneurons in the lamina propria sandwiched between this structure and the tunica muscularis by the method of masked metachromasia to toluidine blue after hot mineral acid hydrolysis. These were also confirmed by lead haematoxylin stain and argyrophilia. The oviduct was serialized into 66 zones. Cells were absent in the first and last 2 zones, and most parts of the isthmus. There was however abundant number of APUD cells in the ampulla which were fusiform shaped and were about $5{\mu}m$ width and also in the juncture, where the cells were of a smaller width ($3{\mu}m$) and were quite numerous reaching 180-200 in some zones. It is concluded that peptide secreting cells are numerous in the oviduct and that this may qualify the oviduct as an endocrine organ.

• Journal of Microbiology and Biotechnology
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• 제13권4호
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• pp.483-486
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• 2003

3'-[S-Methyl-cysteinyl]-3'-amino-3'-deoxy-N,N- dimethyl adenosine, cystocin, is a biosynthesized antibiotic material newly identified from Streptomyces sp. GCA0001. Its structure was found to be similar to puromycin, where the terminal tyrosine is replaced by a methyl cysteine. NMR data prove that the 3-ammo ribose is connected to dimethylaminopurine through the anomeric carbon at 1'-carbon. The methyl cysteinyl unit is connected to the amino unit of ribose by peptide bond. The verification of the structure was performed by comparing the puromycin nucleosides resulted from the hydrolysis of cystocin and puromycin, respectively. Antibiotic activity of cystocin against Streptococcus was found to be two times more potent than that of puromycin.

• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.319-323
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• 1995

A chromogenic mimic of phenlyalanyl-dipeptide, L-phenylalanyl-L-2-sulfanilylglycine (PSG), was synthesized and examined for its usability in leucine aminopeptidase (LAP) assay. The enzyme activity was easily determined by measuring the amount of diazotized adduct of sulfanilic acid released upon hydrolysis of PSG ($\varepsilon^{420}$=18,000/M/cm). Under the experimental conditions employed, PSG showed a Km of 0.063 mM and a Kcat of 1683/min, assessable less than 0.1 $\mu$ g of LAP per milliliter. And the presence of aminopeptidase M (APM) was suggested to be negligible in LAP assay. This novel assay can circumvent the occasional yellow background in biological systems, i.e., serums, etc..

• 한국자기공명학회논문지
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• 제10권2호
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• pp.188-196
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• 2006

A known theonellapeptolide Ie, previously reported in other research group, was isolated from the methanolic extract of the Philippine sponge Theonella swinhoei. The planar structure of this compound was determined on the basis of NMR methods including HMBC and selective HMBC experiments. This is fast and efficient for the dereplication of natural products compared with the MS studies of fragments obtained from complete and partial hydrolysis. The sequence of thirteen amino acids including six N-methyl amino acids in the compound was clearly determined from correlations of extensive HMBC experiments.

• 한국수산과학회지
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• 제32권4호
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• pp.427-431
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• 1999

해조자원의 기능 특성을 밝혀 그 이용도를 증진시키기 위한 연구의 일환으로 일반 해조류의 단백질 함량 및 물추출물과 해조 가수분해물의 ACE 저해효과를 조사한 결과는 다음과 같다. 1 단백질 함량은 김이 $39.6\%$로 가장 높았으며, 파래 $22.1\%$, 미역 $21.1\%$, 우뭇가사리 $18.3\%$, 청각 $15.7\%$, 톳 $12.4\%$, 다시마 $8.2\%$의 순으로 나타났다. 2. 해조 물추출물의 ACE 저해효과는 $50^{\circ}C,\;70^{\circ}C,\;98^{\circ}C$의 세 조건에서 각각 추출한 결과 $70^{\circ}C$에서 추출시 시료 모두에서 가장 높게 나타났으며, ACE 저해율이 가장 높은 $70^{\circ}C$를 기준으로 비교했을 때 우뭇가사리 $10.9\%$, 김 $9.3\%$, 파래 $8.9\%$, 미역 $8.2\%$, 톳 $7.5\%$, 다시마 $7.1\%$, 청각 $7.0\%$로 나타났다. 3. maxazyme과 papain에 의한 해조 가수분해물의 ACE 저해효과는 김이 파래, 미역, 우뭇가사리에 비해 월등히 높았고 pep-tide-nitrogen함량 역시 매우 높았다. 김의 경우 가수분해 8시간에서 ACE 저해효과가 maxazyme $31.3\%$, papain $27.9\%$로 가장 높았고 peptide-nitrogen함량도 이 시간에서 가장 높게 나타났다. 파래의 ACE 저해효과 역시 8시간에서 maxazyme $9.6\%$, papain $8.5\%$로 다른 시간대에 비해 대체로 높았으며 peptide-nitrogen함량은 16시간까지 완만히 증가하였다.

• 대한화학회지
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• 제33권1호
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• pp.3-10
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• 1989

파파인효소의 가수분해반응을 이해하기 위하여 파파인의 활성점에 모여 있는 히스티딘, 시스테인, 및 히스테인-시스테인을 포함하는 양이온성 펩티드-계면활성제를 합성하였다. 이것을 촉매로 사용하여 PNPL을 가수분해 시킬때 pH 7.40에서 촉매의 효율성은 $N^{+}C_{2}AlaC^{12}$과 비교하여 $N^{+}C_{2}HisC_{12}$, $N^{+}C_{2}HisC_{12}$, $N^{+}C_{2}HisCysC_{12}$, 순으로 현저한 증가를 나타내고 그 이유는 $N^{+}C_{2}HisC_{12}$는 이미다졸기, $N^{+}C_{2}CysC_{12}$는 티올기 영향이며, 가장 좋은 촉매효율을 나타내는 $N^{+}C_{2}HisCysC_{12}$은 이미다졸기와 티올기의 상호작용때문이다. 가수분해반응을 촉진시키는 펩티드-계면활성제의 이미다졸기와 티올기들의 활동성을 나타내는 해리상수, pKa는 각각 6.49, 10.50 이고, 기능기에 의한 속도상수, $k^{\ast}_m$는 각각 $7.91{\times}10^{-4}S^{-1}$, $6.00{\times}10^{-4}S^{-1}$이었다. 가수분해에 대한 혼합미셀계의 촉매효과는 파라니트로페닐 에스테르의 알킬기의 탄소수가 증가함에 따라 증가하므로 기능기의 작용외에는 미셀의 소수성 부분과 기질사이의 상호작용에 의하여도 증가됨을 알았다.

• 한국식품영양과학회지
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• 제31권2호
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• pp.263-270
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• 2002

본 연구에서는 casein 펩타이드 분획물이 정상 및 고지방식을 섭취한 흰쥐에서의 혈청 및 조직의 지질 농도에 미치는 섭취효과를 검토하고자 하였다. 정상 지방식이 (7% soybean oil & cholesterol-free; Expt I)를 섭취한 흰쥐는 정상 혈청 지질농도를 나타내는 것으로, 분배설량이 약간 증가하는 경향을 나타내긴 하였지만 이때 casein 펩타이드 분획물군의 혈청,간조직의 지질농도에 대한 효과는 유의적인 차이가 없었다. 하지만, 순환기계질환의 주요 인자인 HDL/LDL비는 친.소수성 펩타이드에서 유의적으로 높은 경향을 나타내었다. 고지방 콜레스테롤식이 (18% beef tallow & 1% cholesterol; Expt II)를 급여하였을 경우, 친.소수성 펩타이드 분획물군에서 분중으로의 총지질, 총콜레스테롤 및 중성지방의 배설량이 유의 적 (p<0.05)으로 또는 증가하는 경향을 나타내었다. 이런 결과, 고지방식이를 급여했을 때 친.소수성펩타이드 분획물군이 casein군에 비해 혈중 및 간조직 중의 지질 농도가 낮아지는 경향을 나타냈다. 또한 HDL/LDL비도 casein군에 비해 친.소수성 펩타이드 분획물군에서 높게 관찰되는 것으로, 이는 고 혈증 위험요소를 저하시키는 효과가 있는 것으로 사료되었다. 친.소수성 펩타이드 분획물(CL & CB)의 아미노산 조성 결과, 친.소수성 펩타이드 식이의 glycine과 methionine함량은 casein 식이의 조성과 거의 비슷한데, arginine과 lysine함량은 casein 식이의 조성과 상당히 달랐다. 또한 혈중 지질농도를 낮추는 것으로 보고되어지는 arginine/lysine 비와 glycine/methionine 비는 친.소수성 펩타이드 분획물 식이(CL & CB)에서 낮게 관찰되었다. 이러한 결과는 동물실험 결과와 같이 고찰해볼 때, 아미노산 조성이 혈중 및 조직 중의 지질저하 효과에 미치는 영향이 그다지 크지 않은 것으로 사료되었고, 앞으로 이에 대한 연구가 더욱 필요하였다. 친.소수성 casein 펩타이드 분획물의 지질 대사에 미치는 영향을 관찰하여 보았을 때, 고지혈증 및 고콜레스테롤혈증 흰쥐에서 혈중 및 간조직의 지질함량을 저하 시키는 효과가 있는 것으로 나타났다. 이에 가능한 기전으로는 분중으로의 지질 배설량을 증가시킨 것에 기인한 것으로 해석되었으며, 섭취기간이 길어질수록 효과가 확실해질 것으로 기대되었다. 또한 casein 펩타이드 분획물의 아미노산 조성비의 차이라기보다는 펩타이드 자체의 효과임이 시사되었다.

• 한국수산과학회지
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• 제42권5호
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• pp.426-433
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• 2009

Fish scales have potential in functional food preparation due to their antioxidant and antihypertensive properties. We investigated the angiotensin I converting enzyme (ACE) inhibitory activity of Tilapia mossambica scale extracts. Hydrolysates of tilapia scales were prepared by enzymatic extraction using five proteases (${\alpha}$-chymotrypsin, Alcalase, Kojizyme, Protamex and trypsin) after scales were treated with hot water for 3 hr. Scale enzymatic hydrolysates prepared using both hot water and enzyme treatments exhibited elevated hydrolysis (about 25%-55%) compared to only enzyme treatment (about 15%-45%). Enzymatic hydrolysates (1 mg/mL) prepared by both hot water and enzyme treatments also showed significantly increased ACE inhibitory activities from about 20%-75%. The pattern of ACE inhibitory activities was similar to the degree of hydrolysis. Alcalase and ${\alpha}$-chymotrypsin hydrolysates displayed the highest ACE inhibitory activities ($IC_{50}$ = 0.83 mg/mL and 0.68 mg/mL, respectively). In addition, the ACE inhibitory effects of $IC_{50}$-chymotrypsin hydrolysates increased with decreasing molecular weight (5 kDa>, 10 kDa> and 30 kDa>), with the 5 kDa> fraction displaying the highest ACE inhibitory activity (about 89.9% and $IC_{50}$ = 0.1 mg/mL). We suggest that the peptide compounds of enzymatic hydrolysates prepared from tilapia scale enhances ACE inhibitory activity and might be useful as an antihypertensive material.

• 대한화학회지
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• 제5권1호
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• pp.33-37
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• 1961

We have shown that carboxy-peptidase destroys the biological activity of angiotensin octa-and deca-peptides. Since Proline occurs as the seventh amino acid from the amino end of the chain and since carboxypeptidase does not cleave proline from a peptid chain, it is evident that the heptapeptid H.asp-arg-val-tyr-ileu-his-pro.OH is formed by this hydrolysis. This peptide must then be biologically inactive. In order to determine whether the phenyl group of the C-terminal amino acid was the necessary requirement for biological activity of the octapeptide, $ala^8$ angiotensin octapeptide(amino acids of peptides numbered from amino end) was synthesized. For this synthesis the four dipeptides were prepared: carbobenzoxy-L-prolyl-L-alanine-P-nitrobenzyl-ester, m.p. $134-135^{\circ}C,$ carbobenzoxy-L-isoleucyl-imidazole benzyl-L-histidine methyl ester, m.p. $114-116^{\circ}C,$ carbobenzoxy-L-valyl-L-tyrosine hydrazide and carbobenzoxy B-benzyl-L-aspartyl-nitro-L-arginine. The first three dipeptides were obtained as crystalline compounds. Imidazole-benzyl-L-histidine was used in the hope that it would block the histidine imidazole against side reactions in steps subsequent to the formation of the C-terminal tetrapeptide. Also, it was through that the imidazole benzylated peptides would be easier to crystallize. This, however, was not the case. The tetrapeptide, carbobenzoxy-L-isoleucyl-L-im, benzyl-histidyl, L-prolyl-L-alanine-nitrobenzyl ester was not obtained in a crystalline form. Neither could the mono-or dihydrobromide of the tetrapeptide free base be induced to crystallize. Carbobenzoxy-L-valyl-L-tyrosine azide was condensed with the tetrapeptide free base to yield the protected hexapeptide; carbobenzoxy-L-valyl-L-tyrosyl-L-isoleucyl-L-im, benzyl, histidyl-L-Prolyl-L-alanine-nitrobenzyl ester. Upon removal of the carbobenzoxy group with hydrogen bromide in acetic acid an amorphous free base hexapeptide ester was obtained. This compound gave the correct C, H, N analysis and contained the six amino acids in the correct ratio. The octapeptide was obtained by condensing this hexapeptide with carbobenzoxy-B-benzyl-L-aspartyl-nitro, L-arginine using the mixed anhydride method of condensation. This amorphous product was proven to be homogenous by chromatography in two solvent systems and upon hydrolysis yielded the eight amino acids in correct ratio. The five protecting groups were removed from the octapeptide by hydrogenolysis over palladium black catalyst. Biological assay of the free peptide indicated that it possessed less than 0.1 per cent of both pressor and oxytocic activity of the phenylalanine8 angiotensin. This suggests that the phenyl group is a point of attachment between angiotensin and its biological receptor site.