Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acidic extracts of washed, ejaculated human spermatozoa contain, besides acrosin, two proteinase inhibitors, a trypsin-chymotrypsin (elastase) inhibitor (HUSI-I) and a trypsin-acrosin inhibitor (HUSI-II). Using the indirect immunofluorescence technique these inhibitors could be localized in the spermatozoa. Ejaculated spermatozoa were treated with monospecific antibodies raised in rabbits against HUSI-I and HUSI-II, respectively, and with fluorescein-labeled IgG from goat directed against the rabbit IgG. If acetone-fixed spermatozoa were used, fluorescence appeared only in a small ring near or at the equatorial segment of the spermatozoa. After prefixation of washed spermatozoa with 0.36% formaldehyde, however, distribution of both inhibitors in the region of the acrosomal caps could clearly be demonstrated. Present results suggest that they are attached at the plasma membrane. Obviously, in the case of human spermatozoa the inhibitors are relatively easily detached together with the membrane so that prefixation is necessary to achieve proper localization.
 ...
PMID:Localization of seminal plasma proteinase inhibitors in human spermatozoa as revealed by the indirect immunofluorescence technique. 79 87

An acid stable protease inhibitor was isolated from human bronchial secretion. Two important stages of the purification procedure were affinity chromatography on trypsin bound to Affi-Gel 10 and ion-exchange chromatography on SP-Sephadex C-50. The isolated inhibitor appeared as a single band on analytical disc electrophoresis and eluted as a homogeneous protein peak on gel filtration on Sephadex G-75 corresponding to a molecular weight of about 10500. Amino acid analyses showed no tryptophan or histidine and as N-terminal amino acid tyrosine. No glucosamine or galactosamine was detected. The results of the analyses suggest that the purified inhibitor is identical to the low molecular weight trypsin-chymotrypsin inhibitor of human seminal plasma (HUSI-I).
 ...
PMID:Isolation and partial characterization of a low molecular weight acid stable protease inhibitor from human bronchial secretion. 88 Nov 64

Human seminal plasma contains two acid-stable proteinase inhibitors, HUSI-II (Mr approximately 6500) and HUSI-I, (Mr approximately 11 000) with different inhibition specificities. The inhibitory activity of HUSI-II is strongly limited to trypsin and acrosin; both enzyme-inhibitor complexes are very stable (e.g. bovine trypsin-HUSI-II complex: Ki = 1 x 10(-10)M; human acrosin-HUSI-II complex: Ki = 2.7 x 10(-10)M). The inhibitor from human seminal plasma HUSI-II may therefore be seen as the natural antagonist of the sperm protease acrosin. In addition to pancreatic trypsin and alpha-chymotrypsin, HUSI-I forms strong complexes with neutral proteases of the lysosome-like granules from human granulocytes, for example, the elastase (Ki = 2.5 x 10(-9)M) and cathepsin G, the chymotrypsin like protease (Ki = 7 x 10(-8)M).
 ...
PMID:Inhibitors of acrosin and granulocyte proteinases from human genital tract secretions. 99 78

An inhibitor of the serine proteinases human leucocyte elastase (EC 3.4.21.37), of cathepsin G (EC 3.4.21.20) and of trypsin (EC 3.4.21.4) has been purified from human articular cartilage. The apparent Mr of the cationic (pI greater than 10) protein was determined to 15,000 by SDS/PAGE. It was shown to cross-react in Western blot with a specific antibody to a recombinant-derived serine-proteinase inhibitor of human mucous secretions. Identity of both inhibitors is indicated by the determination of the N-terminal amino acid sequence of the cartilage-derived serine-proteinase inhibitor. In all 24 residues the cartilage inhibitor was shown to be identical with the human secretory leucocyte proteinase inhibitor ('SLPI'). The inhibitor molecule may play a crucial role in the protection of cartilage matrix proteins against proteolytic attack.
 ...
PMID:Purification of a serine-proteinase inhibitor from human articular cartilage. Identity with the acid-stable proteinase inhibitor of mucous secretions. 200 Dec 42

Horse seminal plasma does not possess a proteinase inhibitor corresponding to human HUSI-I (human seminal plasma inhibitor). Instead a protein complex of high relative molecular mass (Mr) containing proteinase inhibitory activity was detected, which was called horse seminal plasma protein complex or HSPC. The compound had a broad enzyme-inhibiting spectrum. Its Mr was estimated to be 800 000 and it was composed of 7 different polypeptides with Mr values ranging from 11 000 to 30 000. Its carbohydrate content was between 3.5% and 5%. Despite the high molecular mass, the complex was soluble in diluted perchloric acid and did not lose its biological activity. The high recovery of seminal plasma protein (69%) after perchloric acid treatment, the unaltered immunoelectrophoretic precipitation pattern of the perchloric acid soluble part of seminal plasma, and the similarity of the polypeptide patterns of unfractionated seminal plasma and HSPC suggest that HSPC is one of the major components of horse seminal plasma. In addition to HSPC, horse seminal plasma contained a group of three electrophoretically distinguishable proteinase inhibitors, corresponding roughly to a Mr of 6500. They inhibited only trypsin. The similar Mr values and the identical narrow enzyme specificity suggest that they are isoinhibitors and may be analogues of human HUSI-II (human seminal plasma inhibitor). The lack of a HUSI-I analog in the horse is discussed in relation to a previously made observation that horse tracheobronchial fluid contains no detectable perchloric acid-soluble proteinase inhibitors.
 ...
PMID:Proteinase inhibitors of horse seminal plasma. A high molecular mass, acid-soluble proteinase inhibitor. 299 13

Human mucous secretions contain a proteinase inhibitor which is produced locally and inhibits, besides trypsin and chymotrypsin, granulocytic elastase and cathepsin G as well as mast cell chymase and tryptase. The various inhibitors isolated from different sources (bronchial mucus, parotid secretion, seminal plasma, cervical mucus, etc.) and named accordingly (bronchial mucus inhibitor, BMI; human seminal inhibitor I, HUSI-I; cervical mucus inhibitors, CUSI; antileukoprotease, ALP; secretory leukocyte protease inhibitor, SLPI) proved to be identical or derived from a mature inhibitory protein encoded by a single gene of the human genom. Therefore, this inhibitor should be named mucus proteinase inhibitor, MPI. Such a neutral terminus would help to avoid misleading interpretations of already published data and also of the biological role of this inhibitory protein because the MPI may serve several and different physiological functions.
 ...
PMID:Human mucus proteinase inhibitor (human MPI). Human seminal inhibitor I (HUSI-I), antileukoprotease (ALP), secretory leukocyte protease inhibitor (SLPI). 306 Jan 47

Orthorhombic crystals of the complex formed between bovine alpha-chymotrypsin and a recombinant human mucous proteinase inhibitor (SLPI) were grown. Data to 2.3 A resolution were collected on the area-detector diffractometer FAST. The crystal structure of the complex was solved by Patterson search techniques using chymotrypsin as a search model. A cyclic procedure of modeling and crystallographic refinement enabled the determination of the SLPI structure. The current crystallographic R-value is 0.19. SLPI has a boomerang-like shape with both wings comprising two well separated domains of similar architecture. In each domain the polypeptide chain is arranged like a stretched spiral. Two internal strands form a regular beta-hairpin loop which is accompanied by two external strands linked by the proteinase binding segment. The polypeptide segment of each domain is interconnected by four disulfide bridges with a connectivity pattern hitherto unobserved. The reactive site loop of the second domain has elastase and chymotrypsin binding properties. It contains the scissile peptide bond between Leu72I and Met73I and has a similar conformation to that observed in other serine proteinase protein inhibitors. Eight residues of this loop, two of the adjacent hairpin loop, the C-terminal segment and Trp30I are in direct contact with the cognate enzyme. The binding loop of the first domain (probably with anti-trypsin activity) is disordered due to proteolytic cleavage occurring in the course of crystallization.
 ...
PMID:The 2.5 A X-ray crystal structure of the acid-stable proteinase inhibitor from human mucous secretions analysed in its complex with bovine alpha-chymotrypsin. 336 16

It was shown previously that human bronchial mucus contains an acid-stable proteinase inhibitor directed against trypsin and chymotrypsin, polymorphonuclear granulocyte elastase and cathepsin G. In addition to this well-characterized inhibitor, designated here as BSI-ATE (identical with the inhibitor HUSI-I from human seminal plasma or antileucoprotease), another acid-stable inhibitor BSI-E is present in the mucus which exerts inhibitory activity towards porcine pancreatic and human granulocytic elastase, but not against trypsin, chymotrypsin, or granulocytic cathepsin G. This elastase-specific inhibitor was isolated by affinity chromatography. Its molecular mass and its amino acid composition are very similar to those of BSI-TE. An immunological cross-reactivity between both inhibitor species was not observed. In the mucus of patients suffering from obstructive airway disease the elastase-specific inhibitor is not present in the free form but can be liberated by acidification.
 ...
PMID:An elastase-specific inhibitor from human bronchial mucus. Isolation and characterization. 691 99

The apparent preferential expression of the elastase/cathepsin G protease inhibitor antileukoproteinase (ALP) in endometrium of species with epitheliochorial placenta suggests mechanisms of transcriptional regulation unique to these mammalian species. To begin to define the cis-acting regulatory elements involved in the endometrial transcription of the ALP gene, the porcine ALP gene was isolated and characterized. The porcine gene spans at least 13 kb and consists of 5 exons and 4 introns. This genomic structure, except for an additional exon, is similar to that of the human gene where the first three exons encode the signal peptide, trypsin/cathepsin G binding region, and elastase binding region, respectively. The positions of the 16 cysteine residues in exons 2 and 3 of the human gene are conserved in the porcine gene. The porcine gene contains a TATA box at -29 nucleotide (nt), and sequences with limited homology to those which might bind the transcription factors AP-1, AP-2, Sp-1 and Oct-1. The functional promoter activity of the ALP-5' flanking DNA was examined using chimeric ALP-chloramphenicol acetyl transferase (CAT) DNA constructs, after transient transfection in human (ECC-1, Ishikawa) and rabbit (HRE-H9) endometrial and human trophoblastic (JEG-3) cell lines. A 887 nt fragment of the ALP-5'-flanking region (-887ALP-pCAT-E) was active in these cell lines, with the highest promoter activity observed in the ECC-1. Progressive 5' deletion of the 887 nt fragment up to -243 nt had no effect on CAT gene expression in all cell lines, relative to the longest construct.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Chromosomal organization of the gene encoding porcine antileukoproteinase and functional analysis of the promoter region in endometrial and placental cells. 790 70

Hexahydrophthalic anhydride (HHPA), an industrially important chemical, is a highly allergenic compound. The aim of this work was to identify proteins in nasal lavage fluid (NLF) that form adducts with HHPA. Such bindings may induce production of specific immunoglobulin E (IgE) or affect physiological mechanisms of the proteins. NLF was obtained from HHPA-exposed volunteers, workers and exposed guinea pigs. HHPA-binding proteins were visualized with immunoblotting using a polyclonal antiserum against HHPA. The proteins were excised from sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) gels, digested with trypsin and identified by tandem mass spectrometry (MS/MS) and database searches. The antiserum was found to be specific for HHPA-bound proteins. In vivo formed HHPA-binding proteins in humans were identified as antileukoproteinase, immunoglobulin G (IgG), immunoglobulin A (IgA), serum albumin and lactoferrin. In addition, several proteins binding to HHPA were found in NLFs from guinea pigs but these could not be identified from database searches. Hypotheses for development of airways diseases by adduction of this allergenic compound to the NLF proteins in humans were established.
 ...
PMID:In vivo conjugation of nasal lavage proteins by hexahydrophthalic anhydride. 1472 81


1 2 Next >>