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P Petrilli

Publications and source records attributed to P Petrilli.

10 recordsLinked to original sources

A new procedure for peptide alignment in protein sequence determination using fast atom bombardment mass spectral data.

A computer program allowing the correct alignment of peptides generated by a first cleaving agent during protein sequence determination studies has been developed. The program elaborates data obtained from fast atom bombardment mass spectrometric analysis of different digests of the protein. The recorded mass values are used to identify peptides in these digests that overlap peptides from the first cleavage, thus making it possible to establish unambiguously the correct order of these peptides in the protein chain. This procedure has been tested on a model protein by reconstructing the complete sequence of human beta-globin chain, determining the correct alignment of 14 tryptic peptides.

Amino Acid Sequence

PROLANG: an expandable software in protein chemistry.

PROLANG is an improved version of the PROSOFT program. Improvements to the old commands were made and new ones were added, PROLANG is an open software that users with BASIC programming experience can easily expand.

Chemical Phenomena

PROSOFT: a general purpose software in protein chemistry.

Applesoft and 6502 Assembler software was designed to quickly perform operations commonly encountered in protein chemistry. It was not designed for a specific application but can be conveniently used to speed up the determination of protein primary structure.

Algorithms

Digestion by pancreatic juice of a beta-casomorphin-containing fragment of buffalo beta-casein.

Degradation by pig pancreatic juice of a beta-casomorphin-containing fragment (tryptic peptide corresponding to residues 49-68 of buffalo beta-casein) was investigated. The FAB/MS (fast atom bombardment mass spectrometry) technique was used to identify the fragments produced by the concerted action of pancreatic proteases. Pancreatic juice, under our experimental conditions, is not able to release beta-casomorphins or morphiceptin from the tryptic peptide sequence. Furthermore, the present report shows that the rapid hydrolysis of a peptide bond by a single protease can prevent the cleavage of peptide bonds by a different protease. Therefore the formation of some peptides in the gastrointestinal tract can depend on the protease ratio.

Animals

Assignment of phosphorylation sites in buffalo beta-casein by fast atom bombardment mass spectrometry.

Fast atom bombardment mass spectrometry has been applied to the localization of phosphorylation sites in buffalo beta-casein. Two complementary strategies of identification are described. Phosphorylated residues in the tryptic peptide Tp 1 have been assigned by measuring the masses of peptide fragments obtained by enzymatic degradations. The phosphoserine residue in peptide Tp 2 has been identified by determining the intact molecular weight and confirmed by partial sequence information. This rapid and sensitive procedure appears of a great interest in structural studies of a wide range of post-translational modifications in proteins.

Amino Acid Sequence

Does casomorphin have a functional role?

Degradation of buffalo beta-casein by various physiological enzymes was studied. Digestion with gastric and pancreatic proteases plus leucine aminopeptidase did not release casomorphins but a putative precursor (procasomorphin) which was further digested by brush border peptidases into peptides differing from casomorphins.

Amino Acids

Buffalo alpha S0-casein: isolation and characterization.

A method for the preparation of alpha S0-casein, and for the preparation of alpha S1-casein fractions 1 and 2 from buffalo casein are described. The amino acid composition and phosphorus content of alpha S0-casein are given and compared with those of other alphaS-caseins.

Amino Acids