• Mass Spectrometry Letters
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• 제6권3호
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• pp.80-84
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• 2015

Here, we demonstrate the use of MALDI-TOF as a fast and simple analytical approach to evaluate the DNA-binding capability of various peptides. Specifically, by varying the amino acid sequence of the peptides consisting of lysine (K) and tryptophan (W), we identified peptides with strong DNA-binding capabilities using MALDI-TOF. Mass spectrometric analysis reveals an interesting novel finding that lysine residues show sequence selective preference, which used to be considered as mediator of electrostatic interactions with DNA phosphate backbones. Moreover, tryptophan residues show higher affinity to DNA than lysine residues. Since there are numerous possible combinations to make peptide oligomers, it is valuable to introduce a simple and reliable analytical approach in order to quickly identify DNA-binding peptides.

• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.798-803
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• 2001

Peptide synthetases produced from various microorganisms are multifunctional enzyme complexes and their substrates are recognized and activated by adenylation domains. To identify the substrate specificity of the peptide synthetase isolated from Bacillus subtilis 713, known to produce an antifungal peptide, two adenylation domains containing the minimal functional portion were expressed and purified. ATP-ppi exchange experiments and kinetic studies revealed that the two adenylation enzymes had a substrate specificity to $_{L}-lysine{\;}and{\;}_{L}-tryptophan$, respectively. In addition, based on a signature sequence comparison, the substrate of the third domain was predicted to be L-glutamic acid. These results suggest that this peptide synthetase is novel because there has been no previous report on a peptide synthetase that uses $_{L}-lysine,{\;}_{L}-tryptophan,{\;}and{\;}_{L}-glutamic$ acid as substrates in that order.

• Applied Biological Chemistry
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• 제22권1호
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• pp.1-9
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• 1979

대두(大豆)의 ${\gamma}-conglycinin$을 정제(精製)하고 그의 물리일(物理一) 화학적(化學的) 성질(性質)을 연구(硏究)하여 다음의 결과(結果)를 얻었다. Gamma-conglycinin은 대두(大豆)의 pH 4.5, 0.2M Nacl 추출액을 Sephadex G-150으로 분리하여 얻은 7S globulin을 DEAE-Sephadex A-50으로 column chromatography하여 정제(精製)하였다. 정제된 ${\gamma}-conglycinin$은 면역전기영동(免疫電氣泳動), polyacrylamide gel 전기영동(電氣泳動)과 gel isoelectric focusing 상으로 순수(純粹)하였다. 등전점(等電點)은 pH 5.4이었으며 질소(窒素) 16.21%, mannose 4.18, glucosamine 1.21%의 함량(含量)이었다. 아미노산 조성(組成)은 일반적(一般的)으로 lysine, dicarboxylic acid와 암모니아태(態) 질소(窒素)의 함량(含量)이 높았고 함황(含黃)아미노산과 tryptophane의 함량(含量)은 낮은 편이었다. Subunit의 등전점(等電點)은 pH $4.5{\sim}5.5$에 분희(分希)하였는데 그중 pH $4.6{\sim}5.0$에 위치(位置)한 것은 분자량(分子量) 38,000의 당(糖) peptide이었으며 pH $5.0{\sim}5.5$의 것은 분자량(分子量) 32,000의 단순(單純) peptide이었다.