The amino acid sequence around the reactive serine of elastase

Sequences, Sequences, and Sequences

“…Somewhat more successful than the 35S-labeling were later experiments with 32p. Some proteins, notably ovalbumin (26), could be labeled with [32p]-phosphate, and some enzymes, such as trypsin and chymotrypsin (27,28), could be labeled in their active centers with [32p]-diisopropyl phospho fluoridate (DFP). In this way just one or two residues in a whole protein were labeled, and if a partial hydrolysate were fractionated on a two-dimensional paper system and autoradiographed a relatively simple picture was obtained.…”

“…For instance, information could be obtained by comparing autoradiographs of ionophoreses of partial acid hydrolysates of 32P-Iabeled proteins. In this way it was shown that the sequence around the reactive serine in elastase was the sarne as that in trypsin and chymotrypsin (27). Each labeled residue gave a specific pattern of bands or "fingerprint," and tech niques were worked out for identifying the sequences by autoradiographic methods without carrying out an amino acid analysis.…”

The metabolism of potassium l-serine O[35S]-sulphate in the rat

“…have pointed out that the coexistence of desulphating and sulphating mechanisms could explain why it has not been possible to achieve the enzymic sulphation of L-serine by rat-liversupernatant preparations (Spencer, 1960;. L-Serine and its phosphorylated derivatives occupy important positions in intermediary metabolism and are involved in the active centres of a number of enzyme systems (Schaffer, Harshman & Engle, 1955;Anderson & Joll6s, 1957;Hartley, Naughton & Sanger, 1959). The possibility therefore exists that a specific desulphating enzyme system for sulphated L-serine residues might be of importance in maintaining the metabolically reactive hydroxyl group of the amino acid in an unesterified form.…”

Collagenases and Elastases

“…B.5), Hartley et al (188) and Naughton et al (328a) prepared an enzyme-inhibitor complex with radioactive DFP, hydrolyzed it, separated the peptides on a CM column (188) or by paper ionophoresis (328a) and determined the sequence of amino acids around the reactive serine group. B.5), Hartley et al (188) and Naughton et al (328a) prepared an enzyme-inhibitor complex with radioactive DFP, hydrolyzed it, separated the peptides on a CM column (188) or by paper ionophoresis (328a) and determined the sequence of amino acids around the reactive serine group.…”