PubMed Health⌕ Search

Biomedical subjects

P Petrilli

Publications and source records attributed to P Petrilli.

17 recordsLinked to original sources
PubMed1997

PFDB: a protein families database for Macintosh computers. The effectiveness of its organization in searching for protein similarity.

A protein sequence database (PFDB) containing about 11,000 entries is available for Macintosh computers. The PFDB can be easily updated by importing sequences from the PIR collection through the internet. The most important feature of the database is its organization in families of closely related sequences, each family being characterized by its average dipeptide composition [Petrilli (1993), Comput. Appl. Biosci. 2, 89-93]. This allows one to perform a rapid and sensitive protein similarity search by comparing the precalculated family dipeptide composition with that of the query sequence by a linear correlation coefficient. An example of an application in which a new protein was classified by using a sequence of a fragment just 19 residues long is reported.

Albumins↗
PubMed1994

An algorithm to determine protein sequence alignment by utilizing data obtained from a peptide mixture and individual peptides.

With the aim of limiting peptide purification steps and unambiguously ascertaining protein sequences, we have designed and implemented on a personal computer an algorithm to determine sequence alignment by utilizing data obtained from automatic Edman degradation performed on a single peptide mixture and individual peptides. The protein under study is digested by two different hydrolysis methods and fragments are just isolated from one mixture and sequenced, while the second mixture is submitted unfractionated to sequence analysis. The algorithm provides for the exact alignment of the individual peptides using the mixture data for the overlapping. We report an example of application of this approach by utilizing experimental data obtained from a protein of known sequence.

Algorithms↗
PubMed1994

Hydrolysis pattern of procasomorphin by gut proteases from plant parasite Heliothis zea, determined by sequence analyses performed on the unfractionated digestion mixtures.

The digestion pattern of procasomorphin, a putative precursor of beta-casomorphins (beta-casein-derived opioid peptides), by gut proteases from the plant parasite insect Heliothis zea has been determined to evaluate the possibility of introducing in plants the gene encoding for this peptide in order to confer resistance to damage by the insect. The method we used is based on the possibility of deducing the sequence of the fragments produced by proteases at different times of digestion by means of automatic Edman degradation performed on the fragment mixtures without any purification steps. This approach can be considered of general utility in studying the digestion of peptides by a mixture of proteases.

Amino Acid Sequence↗
PubMed1993

Classification of protein sequences by their dipeptide composition.

A simple approach to scan quickly a large protein sequence database for homology is described. The approach used is strictly dependent on the database organization. A database has been compiled in which protein sequences are grouped into families of closely related proteins, each family being characterized by its average dipeptide composition. A new entry in the database can be allocated in a family by comparing its dipeptide composition with the average dipeptide composition of the families.

Algorithms↗
PubMed1991

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↗
PubMed1990

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↗
PubMed1988

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↗
PubMed1987

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↗
PubMed1986

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↗
PubMed1984

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↗
PubMed1981

Reactivity of sulphydryl groups of cytosolic and mitochondrial bovine aspartate aminotransferases.

Reactivity of sulphydryl groups of cytosolic and mitochondrial aspartate aminotransferases from ox heart has been studied. A total of 5 and 7 cysteine residues per monomer are present in cAATo and mAATo, respectively. In native conditions only a single sulphydryl group can be titrated by Nbs2 while the catalytic activity remains unchanged, however in the mitochondrial isozyme the reactivity depends on the functional state of the enzyme. Reactivity toward NEM reveals the existence of a syncatalytic sulphydryl group in the cytosolic isozyme. Titration of cAATo with pMB at pH 8 and pH 5 confirms the existence of two exposed sulphydryl groups with a different reactivity. The results compared with those reported on the corresponding isozymes from pig and chicken heart show that syncatalytic sulphydryl groups are of general occurrence in these enzymes.

Animals↗
PubMed1979

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↗
PubMedDate not supplied

Primary structure of water buffalo beta-casein tryptic and CNBr peptides.

The partial amino acid sequence (70%) of water buffalo beta-casein has been determined by aligning the sequences of tryptic and CNBr peptides along the polypeptide chain of bovine beta-casein. Only five amino acid substitutions are observed. Moreover, as in all the beta-caseins so far investigated, a morphine-like peptide is present.

Amino Acid Sequence↗