Reactive Serine Residue Research Articles

Serine-containing active center of alkaline proteinase of Aspergillus flavus

1. 1. From the soluble portion of the tryptic digest of oxidized diisopropyl [ 32P]-phosphoryl-derivative of alkaline proteinase of Aspergillus flavus a radioactive fragment was isolated and its amino acid composition determined to be Asp 7, Met 1, Thr 5, Ser 8, Glu 4, Pro 3, Gly 7, Ala 9, Val 6, Ile 5, Leu 6, Tyr 2 and Phe 2. 2. 2. Four radioactive peptides were isolated from a partial acid hydrolysate of the slightly soluble portion of the tryptic digest. These peptides provides evidence of the amino acid sequence Gly-Thr-Ser-Met-Ala around the reactive serine residue of alkaline proteinase. This amino acid sequence represents a part of the large tryptic fragment. 3. 3. Similarities in the amino acid sequences of serine-containing active centers of microbial proteinases are discussed.

Studies on Streptomyces griseus protease : II. The amino acid sequence around the reactive serine residue of DFP-sensitive components with esterase activity

1. 1. A highly purified esterase preparation from Streptomyces griseus protease (Pronase), active against benzoylarginine ethyl ester, was inactivated with [ 32P]DFP and hydrolysed with HCl. From the acid hydrolysate, the dipeptides Asp-[ 32P]SerP and [ 32P]SerP-Gly, as well as the tripeptide ASp-([ 32P]SerP, Gly), were isolated. This shows that the amino acid sequence around the reactive serine residue of the enzyme is Asp-Ser-Gly. 2. 2. Two other esterase components from Pronase, active against p-nitrophenl acetate, were inactivated with [ 32P]DFP and hydrolysed in the same manner. On paper electrophoresis at pH 3.5, identical patterns of 32P-labelled peptides were obtained from all three enzyme components. This indicates that the three esterases have the same amino acid sequence at the DFP-reacting site.

A unique amino acid sequence around a reactive serine residue in peptidases from French beans and yeast.

A unique amino acid sequence around a reactive serine residue in peptidases from French beans and yeast.

Concerning the nature of the alpha- and beta-lytic proteases of Sorangium sp.

The α-lytic protease is readily inhibited by diisopropyl phosphorofluoridate (DFP) and the yield of serine phosphate from acid-hydrolyzed, DFP-inhibited enzyme indicates that DFP esterifies one serine residue of the enzyme. Acid digests of enzyme treated with isopropyl methylphosphonofluoridate-32P (sarin) show much the same electrophoretic patterns of 32P-labelled peptides as similar digests of sarin-treated trypsin and chymotrypsin; amino acid analyses and N-terminal amino acid analyses of peptides isolated from the digest confirm that the α-enzyme has the same sequence (Asp-Ser*-Gly-Gly) around the reactive serine residue as the pancreatic enzymes. At present, the α-enzyme is the only microbial "serine protease" which is known to have this sequence. It is also unique as a serine protease in that it has only one histidine residue.The β-lytic enzyme is not inhibited by DFP and shows no evidence of reactivity towards sarin. Its zinc atom can be removed by o-phenanthroline without loss of lytic activity. At present, it cannot be classed in any of the major groups of proteases.

Failure of sarin (isopropyl methylphosphonofluoridate) to react with α-chymotrypsin inactivated by tosyl phenylalanine chloromethyl ketone

Sarin, an inhibitor which binds chymotrypsin at the reactive serine residue in the active site, was reacted with chymotrypsin previously inactivated by N-tosyl- l-phenylalanine chloromethyl ketone (TPCK). TPCK binds a histidine residue in the active site. No significant reaction of sarin was found.

The amino acid sequence around the reactive serine residue in alkaline phosphatase of Serratia marcescens.

The amino acid sequence around the reactive serine residue in alkaline phosphatase of Serratia marcescens.

The amino acid sequence around the reactive serine residue in alkaline phosphatase from Escherichia coli.

The amino acid sequence around the reactive serine residue in alkaline phosphatase from Escherichia coli.

The amino acid sequence around the reactive serine residue of some proteolytic enzymes.

The amino acid sequence around the reactive serine residue of some proteolytic enzymes.

Nature of the reactive serine residue in enzymes inhibited by organo-phosphorus compounds.

Mechanism of Esterase Action: Nature of the Reactive Serine Residue in Enzymes inhibited by Organo-Phosphorus Compounds