Abstract: A method for removing from a peptide the diketone of the methionine residue, and a method for manufacturing a peptide or salt thereof which does not possess an N-terminal methionine residue, characterized by having a peptide or salt thereof which possesses a diketone of the optionally oxidized N-terminal methionine residue react with 3,4-diaminobenzoic acid or a salt thereof in the presence of acetic acid and sodium formate, formic acid and sodium formate, or formic acid and sodium acetate.

Abstract: The present invention provides a method for chemically removing a N-terminal methionine residue selectively, specifically and efficiently from a peptide or a salt thereof having an optionally oxidized methinine residue at its N-terminal. The method reacts a peptide or a salt thereof having an optionally oxidized methinine residue at its N-terminal with an &agr;-diketone derivative, followed by hydrolysis.

Abstract: The present invention provides a method for chemically removing a N-terminal methionine residue selectively, specifically and efficiently from a peptide or a salt thereof having an optionally oxidized methinine residue at its N-terminal. The method reacts a peptide or a salt thereof having an optionally oxidized methinine residue at its N-terminal with an .alpha.-diketone derivative, followed by hydrolysis.

Abstract: A pneumatic nailing machine for driving a nail to a work, comprising: a main unit having a body; a cylinder disposed in the body of the main unit; a nose portion being hollow and continously extending from the main unit, the nose portion having a driver guide hole; a piston slidably inserted in the cylinder; and a driver coupled to the piston in the cylinder, and being slidable between a uppermost position and a lowermost position, wherein the driver and the piston are driven by high pressure compressed air supplied into the cylinder, and the nail supplied to the nose portion is hammered by the driver, the driver including, a base portion positioned near the piston and having a relatively large diamter so as to be substantially equal to an inner diameter of the driver guide hole, wherein the base portion is fitted into the driver guide hole when the driver reaches the lowermost position, and a tip end portion has a diameter so as to be smaller than an inner diameter of the nose portion, wherein the driver is

Abstract: Projected portions 17, 18, 19 are formed at three positions in the middle and on left and right ends of the front surface of a driver 13 of a staple hammer. The width of the projected portion 18 in the middle is smaller than the distance between both leg portions S.sub.3, S.sub.4 of a staple S, and the projected portion 18 is not in contact with the upper surfaces of bends S.sub.1, S.sub.2 of the staple S. Further, the distance between the projected portions 17, 19 on both left and right ends is slightly smaller than the total width of the staple S. The projected portions 17, 19 are located above the bends with radii, and are not in contact with the bends. At the time of hammering, the projected portion 18 in the middle impinges the middle portion of the top surface of the staple S, allowing both leg portions S.sub.3, S.sub.4 of the staple S to ground upon the object to be hammered so as to be expanded.