N-Terminal Sequences of ${\lambda}$-type Bence Jones Proteins

${\lambda}$형(型) Bence Jones 단백질(蛋白質)의 N 말단주변(末端周邊)의 아미노산배열순서(酸配刻順序)에 관한 연구(硏究)

  • Published : 1970.03.31

Abstract

Two peptides (Im pr-M, Im ch-M) derived from Im ${\lambda}-type$ of Bence Jones Protein and one peptide (Ikch-M) from Ik were separated and purified using the Dowex $50{\times}2$ column $(1{\times}20\;cm)$ and Dowex $1{\times}2(0.9{\times}50\;cm)$. The buffer solution was composed of 1% pyridine and IM formic acid in Dowex $1{\times}2$ column. The blocked N-terminal was examined with ninhydrin reaction before and after alkaline hydrolysis, which was fractionated by Dowex $1{\times}2$ column. Pyrro-glutamic acid in N-terminal residue was identified by comparing with the authentic pyrro-glutamic acid through a high voltage electrophoresis (pH 3.5, 3000 V.) after the peptide Im pr-M (PCA. Ser) was cleavaged at the position of serine with cone. (12 N) HCl and the pyrro-glutamic acid was converted to glutamic acid by treating it with N-NaOH for 116 hours at $27^{\circ}C$. The substractive method was applied to find out the sequence of peptides and carboxypeptidase A was employed to release C-terminal residue from the peptide. In present study PCA. Ser in Im Pr-M was isolated from the pronase digested ${\lambda}$-type Bence Jones protein. The yield of the Im Pr-M was 79.6 percent of its theoretical value, based on the molecular weight of Bence Jones Protein. Im ch-M (PCA. Ser Val. Leu) was isolated from the chymotrypsin digested ${\lambda}$-type Bence Jones Protein. The yield of the Im ch-M was 72.2 percent. based on the molecular weight of Bence Jones Protein. Ik ch-M (PCA. Ser. Ala. Leu) was isolated from the chymotrypsin digested ${\lambda}$-type Bence Jones Protein and its yield was 42% based on the molecular weight of Bence Jones Protein.

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. $Im\;Ch-M\;PCA{\cdot}Ser{\cdot}Val{\cdot}Leu$ $Ik\;Ch-M\;PCA{\cdot}Ser{\cdot}Ala{\cdot}Leu1$

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