Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.4.21.4 (trypsin)
42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To clarify the properties and functions of a trypsin inhibitor from Japanese barley in comparison with the inhibitor from Pirkka barley, an inhibitor was isolated from the barley Hordeum distichum L var. emend Lamark by extraction with 1% NaCl, ammonium sulfate fractionation and repeated chromatography on DEAE-cellulose and CM-cellulose. The final purified preparation of the inhibitor was found to be homogeneous by both chromatographic and electrophoretic analysis. The inhibitor was thermostable and was stable over the broad pH range from 2 to 11. No inhibition was observed by heavy metal ions and many reagents at 10(-2) M, except that p-chloromercuribenzoate caused a 69% loss of activity. The inhibitor was subjected to isoelectric focusing at pH 7.51 and its molecular weight was calculated to be 14,200+/-900 by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The apparent dissociation constant for the complex between the inhibitor and trypsin[EC 3.4.21.4] was 1.64 X 10(-7)M with casein as a substrate. One microgram of purified inhibitor inhibited 1.5 mug of pure trypsin in the hydrolysis of alpha-N-benzoyl-DL-arginine-p-nitroanilide. By chemical modification of arginyl residues in the inhibitor with 1,2-cyclohexanedione, the inhibitor was shown to be an arginine inhibitor. The inhibitor contained relatively many basic amino acids and few half cystines as compared with Pirkka barley trypsin inhibitor.
...
PMID:Studies on trypsin inhibitor in barley. I. Purification and some properties. 0 Mar 80

The reactive site peptide bond of the eggplant inhibitor against trypsin [EC 3.4.21.4] was identified by chemical modifications with 1,2-cyclohexanedione, 2,4,6-trinitrobenzenesulfonic acid, acetic anhydride and glyoxal, and by sequential treatments with trypsin and carboxypeptidase B [EC 3.4.12.3]. The inhibitor was significantly inactivated by chemical modifications of arginine residues, but was not affected by lysine modifications. Free arginine was released from the trypsin-modified inhibitor by carboxypeptidase B digestion, accompanied by a marked loss of inhibitory activity. A serine residue was newly exposed at the N-terminal amino acid of the inhibitor after modification with trypsin. The reactive site of the inhibitor against trypsin was concluded to be an arginylseryl bond. The inhibitor was completely inactivated by full reduction of its disulfide bonds.
...
PMID:The reactive site of eggplant trypsin inhibitor. 1 22

Chemical modifications of human plasma alpha1-antitrypsin with reagents which modify lysyl residues (citraconic anhydride, acetic anhydride, formaldehyde and 2,4,6-trinitrobenzenesulfonic acid) and arginyl residued (1,2-cyclohexanedione) were examined with regard to their effect upon the elastase inhibitory capacity of the glycoprotein. 2,4,6-Trinitrobenzenesulfonic acid was employed to quantitate the remaining free amino groups (epsilon-NH2 groups of lysine) and the extent of modifications. Amino acid analysis was utilized in the same capacity for the guanidino groups of arginyl residues. The elastase inhibitory capacity of alpha1-antitrypsin was destroyed following trinitrophenylation, citraconylation and acetylation. Circular dichroism of the native and modified derivatives revealed major changes in conformation following trinitrophenylation and citraconylation while CD profiles of acetylated and reductively methylated derivatives differed from that of the native profile considerably less. Reductively methylated alpha1-antitrypsin retained its elastatse inhibitory capacity. The reaction of 1,2-cyclohexanedione with alpha1-antitrypsin did not effect in a loss in inhibitory capacity. Gel filtration studies of native and modified alpha1-antitrypsin on Sephadex G-100 demonstrated an increased molecular weight presumably through molecular aggregation, in the citraconylated and trinitrophenylated derivatives, but not in the cases of the other derivatives. Based upon these studies and previous investigations of our laboratory, it was concluded that (1) alpha1-antitrypsin is a lysyl inhibitor type (i.e., the reactive site is a Lys-X bond), (2) its interaction with elastase follows a pattern similar to trypsin and chymotrypsin, and (3) the positively charged epsilon-NH2 group of lysine is essential for the maintenance of elastase inhibitory capacity.
...
PMID:Circular dichroism of chemically modified human plasma alpha1-antitrypsin. Interaction with porcine elastase. 31 Mar 16

The single polypeptide chain of about 460 amino acids of porcine pancreatic lipase (EC 3.1.1.3) has been fragmented into five peptides by cyanogen bromide cleavage [Rovery, M., Bianchetta, J. & Guidoni, A. (1973) Biochim. Biophys. Acta, 328, 391--395]. The sequence of the first three cyanogen bromide peptides (CNI, CNII, CNIII), including a total of 234 amino acids, was fully elucidated. Automatic or manual Edman degradation was performed on the different peptides. Fragmentations of the CN peptides were accomplished by digestions with trypsin (after citraconylation or 1,2-cyclohexanedione treatment), chymotrypsin and Staphylococcus aureus external protease. Hydrolysis of unreduced material by pepsin and thermolysin, performed in order to determine the S-S bridge positions, provided useful overlapping peptides. The glycan moiety of lipase is bound to Asn-166. The non-essential tyrosine specifically blocked by diisopropylphosphorofluoridate is Tyr-49 in a cluster of asparagine and glutamine residues. The existence of a highly hydrophobic sequence (206--217) at the C terminus of the CNII fragment is noteworthy.
...
PMID:Porcine pancreatic lipase. Sequence of the first 234 amino acids of the peptide chain. 38 Sep 92

The primary structure of protein L21 from the 50S subunit of Escherichia coli ribosomes has been completely determined by sequencing the peptides obtained by digestion of L21 with trypsin before and after modification of the arginine residues with 1,2-cyclohexanedione, Staphylococcus aureus protease, thermolysin, and pepsin. Automated Edman degradation using a liquid-phase sequenator was carried out on the intact protein as well as on a fragment arising from cleavage with cyanogen bromide. Protein L21 consists of a single polypeptide chain of 103 amino acids of molecular weight 11 565. An estimation of the secondary structure of protein L21 and a comparison with other E. coli ribosomal protein sequences are presented.
...
PMID:Amino acid sequence of the ribosomal protein L21 of Escherichia coli. 38 76

The complete amino acid sequence of the major component myoglobin from the Pacific spotted dolphin, Stenella attenuata graffmani, was determined by the automated Edman degradation of several large peptides obtained by specific cleavage of the protein. The acetimidated apomyoglobin was selectively cleaved at its two methionyl residues with cyanogen bromide and at its three arginyl residues by trypsin. By subjecting four of these peptides and the apomyoglobin to automated Edman degradation, over 80% of the primary structure of the protein was obtained. The remainder of the covalent structure was determined by the sequence analysis of peptides that resulted from further digestion of the central cyanogen bromide fragment. This fragment was cleaved at its glutamyl residues with staphylococcal protease and its lysyl residues with trypsin. The action of trypsin was restricted to the lysyl residues by chemical modification of the single arginyl residue of the fragment with 1,2-cyclohexanedione. The primary structure of this myoglobin proved to be identical with that from the Atlantic bottlenosed dolphin and Pacific common dolphin but differs from the myoglobins of the killer whale and pilot whale at two positions. The above sequence identities and differences reflect the close taxonomic relationship of these five species of Cetacea.
...
PMID:Complete amino acid sequence of the myoglobin from the Pacific spotted dolphin, Stenella attenuata graffmani. 45 57

The complete amino acid sequence of the major component myoglobin from the pilot whale, Globicephala melaena, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequencer. The apomyoglobin was selectively cleaved at the two methionyl residues with cyanogen bromide and the acetimidated apomyoglobin was cleaved at the three arginyl residues by trypsin. From the sequence analysis of four of these peptides and the apoprotein, over 90% of the covalent structure of the protein was obtained. The remainder of the primary structure was determined by sequence analysis of three of the tryptic peptides isolated from the central cyanogen bromide fragment after modification of its single arginyl residue with 1,2-cyclohexanedione. This myoglobin differs from that of the Black Sea dolphin at four positions and from the myoglobin of the killer whale, Pacific common dolphin, and Atlantic bottlenosed dolphin at two positions. The above differences reflect the close taxonomic relationship of these five species of Cetacea. This sequence determination was aided by the use of a Texas Instruments 980A minicomputer system which performed peak integrations for all samples subjected to amino acid analysis.
...
PMID:Complete amino acid sequence of myoglobin from the pilot whale, Globicephala melaena. 65 76

The complete amino acid sequence of the major component myoglobin from the dwarf sperm whale, Kogia simus, was determined by specific cleavage of the protein to obtain large peptides which are readily degraded by the automatic sequenator. Three easily separable peptides were obtained by cleaving the protein at its two methionine residues, and five peptides were obtained from the methyl acetimidated protein by cleavage with trypsin at the four arginine residues. Sequenator analysis of these fragments and the apomyoglobin provided over 80% of the covalent structure of the protein. The remainder of the primary structure was determined by further digestion of the two larger cyanogen bromide fragments with trypsin and staphylococcal protease. To reconfirm many of the substitutions found in this protein, the apomyoglobin was treated with 1,2-cyclohexanedione, and the resulting arginine protected protein was cleaved at its lysine residues with trypsin. This myoglobin differs from that of the sperm whale at 6 positions, and from the other cetacean myoglobins at about 16 positions. The appearance of a histidine residue at position 35 has no precedent in any myoglobin. The substitutions seen at positions 21, 51, and 132 are unique to date for cetacean myoglobins.
...
PMID:The complete amino acid sequence of the major component myoglobin of dwarf sperm whale (Kogia simus). 84 20

Reversible and selective modification of the guanidino group by 1,2-cyclohexanedione or 2,3-butanedione in borate buffer was applied to identify arginine residues in the reactive sites of proteinase inhibitors. The ability of the method to distinguish between arginine and lysine residues was examined. Trypsin inhibitors with arginine at the reactive site were almost completely inactivated within 2 h, e.g. the low-molecular weight inhibitors from soybeans (Kunitz), peanuts and porcine seminal plasma. Inhibitors of the lysine-type were not inactivated by 1,2-cyclohexanedione/borate, e.g. the bovine trypsin/kallikrein inhibitor, the trypsin inhibitors from cow colostrum, porcine pancreas, or snail epidermis (isoinhibitor K from Helix pomatia), and the human alpha1-proteinase inhibitor (alpha1-antitrypsin). However, 2,3-butanedione/borate does not show this high specificity. The method was applied to four high-molecular weight proteinase inhibitors from the albumin gland of the snail (Helix pomatia). All four inhibitors were subject to inactivation by the reagent, indicating an arginine residue at the reactive site. Evidence is given by NMR, UV, and titration data that a complex is formed from 1,2-cyclohexanedione and borate. Due to this complex formation, the amount of free carbonyl component is drastically decreased. Since 1,2-cyclohexanedione without borate lacks the high specificity for arginine residues, the borate complex of the reagent is presumed to be responsible for the high specificity. The new procedure for identification of reactive sites is based on a reversible modification of the guanidium group of the arginine residues.
...
PMID:Determination of arginine in the reactive site of proteinase inhibitors by selective and reversible derivatization of the arginine side chain. 96 25

Pretreatment of an affinity-purified, brain calmodulin (CaM)-dependent phosphodiesterase (EC 3.1.4.17) with p-hydroxyphenylglyoxal (pHPG), a specific arginine-modifying reagent, resulted in a time-dependent loss in CaM-stimulated hydrolysis of cyclic AMP and cyclic GMP with no change in basal, CaM-independent activity. The loss in CaM-stimulated activity was preceded by a transient increase in CaM-dependent activity. Phenylglyoxal was 10-fold more effective than pHPG in promoting the loss of CaM-stimulated activity with a second-order rate constant of 13.3 M-1 min-1. Other arginine-modifying reagents, 1,2-cyclohexanedione and 2,3-butanedione, were not effective. The pHPG-modified enzyme was activated by 100 microM lysophosphatidylcholine to levels comparable to CaM-stimulated activity. The arginyl-modified enzyme was also activated by chymotrypsin and trypsin but not to the extent of the untreated enzyme stimulated with CaM. The presence of CaM during chemical modification with pHPG protected the enzyme from inactivation. Both the extent of activation and the amount of CaM necessary for 50% maximal activation were affected by pHPG treatment of the enzyme. The approximate number of modified arginines estimated by [7-14C]phenylglyoxal incorporation and amino acid analysis after complete inactivation of CaM stimulation was seven residues per catalytic subunit assuming enzyme homogeneity. The Stokes radius and sedimentation coefficient of the enzyme were unchanged by the modification. These results suggest that arginine residues are critical for functional interaction between phosphodiesterase and CaM and that controlled modification can selectively alter CaM-stimulated enzyme activity.
...
PMID:Involvement of arginine residues in the activation of calmodulin-dependent 3',5'-cyclic-nucleotide phosphodiesterase. 283 86


1 2 3 Next >>

---