Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.27 (thermolysin)
 1,894 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein A and C, which are major components of the acidic proline-rich proteins in human saliva, were digested, before or after adsorption to hydroxyapatite, with alkaline phosphatase, trypsin, thermolysin and a proteinase preparation from salivary sediment. The results demonstrate that the binding site is located in the proline-poor N-terminal part of the protein, possibly between residues 3 and 25. Phosphoserine is necessary for maximal adsorption of the proteins to hydroxyapatite. When proteins A and C are adsorbed to hydroxyapatite before proteolytic digestion there is a protection of some of the susceptible bonds in the N-terminal part of the proteins and a gradual removal of the proline-rich C-terminal part. Thermolysin can cleave susceptible bonds in the part of the protein that remains bound to hydroxyapatite, but at least some of the resulting peptides are retained on the mineral. Since the ability of the proteins to inhibit hydroxyapatite formation and to bind calcium is located in the N-terminal proline-poor part, it is possible that these activities are retained after proteolytic digestion of the adsorbed proteins.
 ...
PMID:The nature of the hydroxyapatite-binding site in salivary acidic proline-rich proteins. 23 Aug 18

Absence of precipitation of calcium phosphate salts onto tooth surfaces from human saliva, which is supersaturated with respect to calcium phosphate salts, has been attributed in part to the presence in the salivary secretions of a group of acidic proline-rich phosphoproteins (PRP). These macromolecules are considered to act by adsorbing onto dental enamel where they inhibit surface-induced precipitation of calcium phosphate salts. The inhibitory activity is known to be associated primarily with the amino-terminal region of the PRP. The aim of this study was to determine the features of the primary structure of this molecular segment responsible for inhibitory activity. The 30-residue, amino-terminal segment of PRP-3, which contains the two phosphoserines and 11 of the 13 carboxyl groups present in PRP-3, was obtained by tryptic digestion. This peptide, designated PRP-3(TI), was treated with thermolysin to give the monophosphopeptides, Val-PSer-Gln-Glu-Asp-Val-Pro and Leu-Val-Ile-Ser-Asp-Gly-Gly-Asp-PSer-Glu-Gln, and with alkaline phosphatase to give the dephosphorylated analog, PRP-3(TI)DP. The inhibitory activities of PRP-3(TI) and the derived peptides, a synthetic peptide, phosphoseryl-phosphoserine (PSer-PSer), and O-phosphoserine (PSer), were determined using an assay based on inhibition of seeded precipitation of calcium phosphate. Inhibitory activities, expressed as concentrations of inhibitors required to give standard inhibitory activities, were PRP-3(TI), 0.59 microM; PSer-PSer, 3.5 microM; the two monophosphopeptides, 29 and 32.5 microM; PRP-3(TI)DP, 56 microM; PSer, 329 microM.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Inhibition of calcium phosphate precipitation by human salivary acidic proline-rich proteins: structure-activity relationships. 310 42

The complete amino acid sequence of glycoprotein gp71A of Friend murine leukemia virus (F-MuLV) is presented. The protein moiety of gp71A was digested with Staphylococcus aureus (SV8) protease, trypsin, and thermolysin. The sequences of the peptides were determined by the micro dansyl Edman procedure. gp71A is composed of 445 amino acid residues and contains eight oligosaccharide side chains, which are attached exclusively to asparagine by N-glycosyl bonds primarily in the COOH-terminal half of the polypeptide. gp71A is rich in proline (49 residues), tryptophan (16 residues), and cysteine (19 residues). Proline has the highest molar content (11%) of all amino acids. The prolines cluster in two segments. The most interesting one stretches between residue 233 and residue 283 and contains 18 prolines within 51 amino acids. This proline-rich domain most likely forms a flexible polyproline helix. The comparison of gp70 of Moloney murine leukemia virus (Mo-MuLV gp70) with F-MuLV gp71A revealed that 70 amino acids have been exchanged and 9 residues have been deleted from Mo-MuLV gp70. The most striking alterations have taken place within the large polyproline segment (residues 247 to 281). In this part of the molecule 7 amino acids have been deleted in Mo-MuLV and 18 residues have been replaced. This evidence supports the proposal of Shinnick et al. [Shinnick, T. M., Lerner, R. A. & Sutcliffe, J. G. (1981) Nature (London) 293, 543-548] that this area is a "hot spot" for recombination.
 ...
PMID:Complete amino acid sequence and glycosylation sites of glycoprotein gp71A of Friend murine leukemia virus. 631 May 44

The complete primary structures of the two main forms, PRP-IV and PRP-V, of a proline-rich polypeptide bound in vivo to rat prostatic binding protein has been determined. Their sequences were established using manual Edman degradation of the native polypeptide and of purified fragments derived from trypsin and thermolysin digestions. Both polypeptides contain 38 amino acid residues (Mr = 4397 and 4339); cysteine, methionine, and serine are missing. In spite of the high proline content (21%), no polyproline stretches were detected. PRP-IV and PRP-V show an extensive structural homology and differ only by three substitutions. These amino acid replacements are located in the NH2-terminal part of the molecule at positions 6 (His leads to Pro), 10 (Pro leads to His), and 11 (Asp leads to Gly). Moreover, each component displays a microheterogeneity at several positions in the sequence which indicates that multiple structural variants exist for PRP-IV and PRP-V. These data not only suggest the existence in rat ventral prostate of a multigene family coding for the proline-rich polypeptides but also the occurrence of a pronounced genetic polymorphism for these components. In addition, a remarkable sequence homology is observed between the PRP components and the region of the B chain in the precursor of mouse renin.
 ...
PMID:Proline-rich polypeptides bound to rat prostatic binding protein. The primary structure of the two main components, proline-rich polypeptides IV and V. 668 33