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K Hochstrasser

Publications and source records attributed to K Hochstrasser.

At least 37 records · Page 2Linked to original sources
PubMed1988

Complementary DNA and derived amino acid sequence of the precursor of one of the three protein components of the inter-alpha-trypsin inhibitor complex.

Inter-alpha-trypsin inhibitor is composed of three distinct protein components. These protein components stem from independently encoded and proteolytically processed precursor proteins. Only the structure of the protein component responsible for the inhibitory activity has been established so far. We now present the complete amino acid sequence of the precursor of the second protein component derived from cloned cDNA. The precursor molecule includes both a signal peptide and a propeptide sequence and seems to be further processed prior to the assembly of the inter-alpha-trypsin inhibitor complex.

Alpha-Globulins↗
PubMed1988

The amino-acid sequence of the double-headed proteinase inhibitor from fox (Vulpes vulpes) submandibular glands.

Fox submandibular glands contain a double-headed secretory proteinase inhibitor. Its amino acid sequence was determined. Extensive homologies were found between this inhibitor and the corresponding inhibitors of cat, lion and dog in both domains. As in dog inhibitor the trypsin-inhibiting domain of fox inhibitor contains an Arg residue in the reactive site in contrast to a Lys residue in the inhibitors of cat and lion. Domains I and II of fox inhibitor are structurally related both to the sequenced inhibitors of cat, lion and dog and to the sequenced monovalent secretory pancreatic trypsin inhibitors. In comparison to cat and lion inhibitors the N-terminally extended sequences of fox and dog inhibitors seem to be characteristic for the inhibitor of Canidae.

Amino Acid Sequence↗
PubMed1987

The amino-acid sequences of the double-headed proteinase inhibitors from cat, lion and dog submandibular glands.

Cat and lion submandibular glands each contain a double-headed secretory proteinase inhibitor. Their amino-acid sequences were determined, and the amino-acid sequence of the inhibitor of dog submandibular glands was revised. Extensive homologies were found between these inhibitors in both domains. The trypsin-inhibiting domains of cat and lion inhibitors, however, contain a Lys residue in the reactive site in contrast to an Arg residue in the dog inhibitor. Domains I and II of cat, lion, and dog inhibitors are structurally related both to each other and to the sequenced monovalent secretory pancreatic trypsin inhibitors, Notable differences in inhibitory properties of canine and feline inhibitors are discussed with respect to sequence differences.

Alkylation↗
PubMed1987

The amino-acid sequence of the trypsin-released inhibitor from sheep inter-alpha-trypsin inhibitor.

The amino-acid sequence of the inhibitory part of the sheep serum inter-alpha-trypsin inhibitor (ITI) was determined. The inhibitor is composed of two covalently linked Kunitz-type domains. The reactive site of the C-terminal antitryptic domain contains arginine in position 71 (P1) and glycine in position 73 (P'2), whereas ITI derived inhibitors hitherto investigated contain phenylalanine in these positions. The reactive site of the N-terminal elastase inhibiting domain contains leucine in position 15 (P1) and methionine in position 17 (P'2), as in ITI-derived inhibitors of pig and horse.

Alpha-Globulins↗
PubMed1987

cDNA cloning of human inter-alpha-trypsin inhibitor discloses three different proteins.

Inter-alpha-trypsin inhibitor (ITI) is a serum protein of unknown function. Part of the molecule (formerly called HI30) is closely related to a tumor-derived protein acting as a growth factor for endothelial cells. We screened a human liver cDNA expression library with antibodies raised against human ITI and isolated several clones which could be divided into three groups according to their DNA sequences. The cDNA of the first group codes for a protein composed of alpha 1-microglobulin (alpha 1M) and urinary trypsin inhibitor (UTI) and is identical to that encoded by a clone originally found by screening a human liver cDNA library with oligonucleotides derived from amino-acid sequences of the two Kunitz-type domains of UTI. The proteins derived from the cDNA of the second and the third group of clones are distantly related to each other, but unrelated to the protein derived from group 1 clones. Partial amino-acid sequencing of ITI isolated from serum allowed the verification of large parts of the cDNA-derived amino-acid sequences. The results favour the view that ITI is not a single chain protein, but rather a very tight complex of several components or a mixture of such complexes.

Amino Acid Sequence↗
PubMed1987

[New methods of diagnosing cerebrospinal fluid fistulas using beta 2-transferrin or prealbumin--principles and methodology].

Two new methods were developed to identify pure CSF and CSF in nasal secretion. One method is based on measurement of beta 2-transferrin, a transferrin variant found only in CSF, whereas the other one is based on determination of the albumin-prealbumin ratio. The determination of beta 2-transferrin is made in two steps. Firstly, the protein variants beta 1- and beta 2-transferrin are isolated selectively from the complex protein mixture by an affinity procedure. The transferrin variants are then separated by a highly resolving polyacrylamide gelelectrophoresis and identified by staining. Advantages of the method are that blood or nasal secretion does not disturb the test and that beta 2-transferrin can be identified with high accuracy. Therefore, CSF can be differentiated unambiguously from other secretions. The determination of the ratios of concentration of the proteins albumin and prealbumin by immunoelectrophoresis is a further possibility to identify pure or almost pure CSF. This sensitive method, which is fast and easy to perform, is very helpful in corroborating the diagnosis of a CSF fistula. On the basis of this method one cannot get a false positive result, but a false negative one by high contamination of CSF with blood or nasal secretion. Therefore, the method of beta 2-transferrin determination must be carried out if there is any doubt.

Cerebrospinal Fluid Otorrhea↗
PubMed1985

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, X. The amino-acid sequences of the trypsin-released inhibitors from horse and pig inter-alpha-trypsin inhibitors.

The amino-acid sequences of the acid-resistant inhibitors released from horse and pig inter-alpha-trypsin inhibitor (ITI) by tryptic proteolysis were determined. They are composed of two covalently linked Kunitz-type domains. In both cases the reactive site of their C-terminal antitryptic domains is occupied by arginine as in the homologous human and bovine inhibitors. The reactive site of their N-terminal domain exhibits only a weak interaction with polymorphonuclear granulocytic elastase and is occupied by leucine as in the strong elastase inhibitor released from bovine ITI. The differences between inhibitory activities of the ITI-derived inhibitors from horse, pig, and cattle are discussed on the basis of sequence differences in position P'2.

Alpha-Globulins↗
PubMed1985

Human inter-alpha-trypsin inhibitor: localization of the Kunitz-type domains in the N-terminal part of the molecule and their release by a trypsin-like proteinase.

The N-terminal amino-acid sequence of human ITI has been found to be identical with that of the acid-stable human 30-kDa inhibitors (HI-30) from urine, serum, and those released from inter-alpha-trypsin inhibitor by trypsin or chymotrypsin. Serum HI-30 and HI-30 released by trypsin differ from the urinary inhibitor by an additional C-terminal arginine residue. Compared to these two inhibitors the inhibitor released by chymotryptic proteolysis is elongated C-terminally by an additional phenylalanine residue. These results strongly favour HI-30 as the N-terminus of the inter-alpha-trypsin inhibitor and its release from this inhibitor in vivo by cleavage of the Arg123-Phe124 peptide bond by trypsin-like proteinases.

Alpha-Globulins↗
PubMed1985

[Clinical relevance of protease inhibitors in nasal secretions].

The normal human nasal mucous membrane is protected against negative effects of proteases by special inhibitors. This inhibitor pool consists of both secretory-specific and humoral inhibitors. A method is presented to determine the function of protease inhibitors in nasal secretion. Investigations have been carried out on secretions of healthy subjects, as well as patients suffering from sinusitis. The differences are illustrated. The results enable an evaluation of the degree of infection; the course of the disease can be documented. A possibility of producing synthetic inhibitors for therapy is discussed.

Blood Proteins↗
PubMed1984

Isolation of acid-resistant urinary trypsin inhibitors by high performance liquid chromatography and their characterization by N-terminal amino-acid sequence determination.

Two crude fractions of acid-resistant trypsin inhibitors (apparent molecular masses 44 and 20 kDa, respectively) were prepared from human urine by gel permeation chromatography. From both preparations the pure inhibitors were isolated by high performance liquid chromatography (HPLC). Their N-terminal amino-acid sequences were determined and compared with those of HI-30 and HI-14 as isolated by reversible binding to either immobilized trypsin or immobilized chymotrypsin. The N-terminal amino-acid sequence of the high-molecular mass inhibitor UI-I isolated by HPLC was identical with those of HI-30 and UI-C-I isolated via immobilized trypsin or chymotrypsin, respectively. The low-molecular mass inhibitors UI-II and UI-C-II differ from HI-14 by the N-terminal extension Glu-Val-Thr-Lys-when obtained by HPLC or by the extension Thr-Lys-when obtained via immobilized chymotrypsin, respectively. The comparison of these N-termini with the amino-acid sequence of HI-30 (Ala1-...-Val16-Thr-Glu-Val-Thr-Lys-HI-14) defines the low molecular urinary trypsin inhibitors as proteolytic degradation products of the high-molecular urinary inhibitor. Proteolysis may occur at different bonds. The existing discrepancies in molecular architecture and in molecular masses of the urinary trypsin inhibitors are discussed.

Amino Acid Sequence↗
PubMed1983

Isolation and characterization of an inter-alpha-trypsin inhibitor-IgG complex from human serum.

Inter-alpha-trypsin inhibitor is a human serum protease inhibitor of Mr 180 000 which may release physiological derivatives. A complex between IgG and an inter-alpha-trypsin inhibitor derivative of Mr 30 000 has been recently detected in human serum and was found to be inactive against trypsin, in contrast with the known inhibitory activity of the free 30-kDa derivative. The present study deals with detailed characterization of an inter-alpha-trypsin inhibitor-IgG complex following its purification by affinity chromatography techniques (anti-inter-alpha-trypsin inhibitor immunoadsorbent and Protein A-Sepharose) in mild conditions. The resulting product reacted simultaneously with anti-IgG and anti-inter-alpha-trypsin inhibitor antibodies. This complex contained Mr 180 000 inhibitor at least to some extent. It migrated in the beta-gamma zone in agarose; its molecular weight was estimated to be 1 500 000 or more; part of it displayed covalent bonding between inter-alpha-trypsin inhibitor and IgG; it had a trypsin inhibitor activity. Immunoelectrophoresis allowed one to demonstrate the native complex in serum owing to the use of anti-inter-alpha-trypsin inhibitor and anti-gamma radioactively labelled antibodies. The double immunoreactivity thus evidenced proved to be heterogeneous with respect to its level and location in the native as well as in the purified complex.

Alpha-Globulins↗
PubMed1983

An elastase-specific inhibitor from human bronchial mucus. Pathogenesis in lung emphysema.

Under physiological conditions human bronchial mucus contains an elastase-specific inhibitor which is quite different from hitherto known inhibitors: alpha 1-antitrypsin, HI-30, and BSI-TE. In bronchial mucus of 100 patients suffering from obstructive airway disease the amount of this inhibitor specific against elastase from both pancreas and polymorphonuclear neutrophilic leucocytes was measured. A group of 18 patients showed no inhibitor in their native mucus rather than free elastolytic activity. Another group of 82 patients had no elastolytic activity in their native mucus but free anti-elastolytic activity together with varying amounts of elastase-specific inhibitor bound to proteases. In a total of 20 cases from both groups the inhibitor was not detectable, neither in a free nor in a complexed form. Presuming that there is no hereditary deficiency involved, a strong importance of inactivating reactions such as oxidation is concluded.

Bronchi↗
PubMed1983

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, VII. Determination of the amino-acid sequence of the trypsin-released inhibitor from bovine inter-alpha-trypsin inhibitor.

An acid-labile proteinase inhibitor, quite similar to human inter-alpha-trypsin inhibitor, was isolated from bovine serum. An acid-resistant 30-kDa inhibitor, exhibiting properties similar to human HI-30, was also isolated. Upon limited proteolysis of both bovine inhibitors, active 14-kDa domains are released which are identical with respect to molecular mass and acid resistance. The amino-acid sequence determination of these fragments revealed a strong homology to the corresponding human inhibitor HI-14 which is characterized by two covalently linked Kunitz-type domains. The reactive-site residue is leucine in the N-terminal domain (in the human inhibitor methionine) and arginine in the C-terminal domain in both bovine and human inhibitor.

Alpha-Globulins↗
PubMed1983

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, VII. Characterization of the bovine inhibitor as double-headed trypsin-elastase inhibitor.

The acid-resistant 14-kDa inhibitor BI-14, released from bovine inter-alpha-trypsin inhibitor, consists of two tandem Kunitz-type domains, and is of a double-headed nature. The Arg-Thr bond connecting both domains was cleaved and the two inhibitory domains were separated. The N-terminal domain is an inhibitor of bovine chymotrypsin and elastases from porcine pancreases and human polymorphonuclear granulocytes, whereas the C-terminal domain interacts with trypsin, plasmin, and chymotrypsin. In the intact inhibitor BI-14 both domains interact independently with the proteinases.

Alpha-Globulins↗
PubMed1983

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, IX. Isolation and characterization of the inhibitory parts of inter-alpha-trypsin inhibitors from several mammalian sera.

The inhibitory parts of inter-alpha-trypsin inhibitor-like proteins from several mammalian sera (sheep, goat, horse, donkey, pig, rabbit, rat and dog) were released by limited proteolysis with trypsin and were isolated by reversible binding to immobilized trypsin. The inhibitors are very similar with respect to their stability in acids, molecular masses and amino-acid compositions. They are different, however, in their inhibitory properties. In view of the known covalent structures of the inhibitory parts of the human and bovine inhibitors, homologous covalent structures consisting of two tandem Kunitz-type domains are suggested also for the isolated inhibitors. Bovine trypsin, bovine chymotrypsin and porcine plasmin are inhibited by all investigated inhibitors, most likely via their C-terminal domain. The inhibitors from horse, donkey, rabbit, rat and dog serum interact also with elastase from human polymorphonuclear granulocytes, those from sheep, goat and pig serum inhibit in addition porcine pancreatic elastase and bovine chymotrypsin via their N-terminal Kunitz-type domain. It is supposed that the amino-acid residue in position P1 of the N-terminal Kunitz-type domain is responsible for the characteristic inhibitory properties of each inhibitor.

Alpha-Globulins↗
PubMed1983

Elastase inhibition by the inter-alpha-trypsin inhibitor and derived inhibitors of man and cattle.

The inhibitory properties of HI-14 and BI-14, the active 14-kDa parts released from the corresponding human and bovine inter-alpha-trypsin inhibitors, are compared. The structurally homologous inhibitors composed of two tandem Kunitz-type domains differ in their inhibitory specificity, although the reactive site residue in position P1 is occupied by identical (arginine in the C-terminal domain II) or similar (methionine and leucine in the N-terminal domain I of HI-14 and BI-14, respectively) amino-acid residues. The N-terminal domain I of HI-14 is completely inactive against chymotrypsin and pancreatic elastase, whereas BI-14 is a strong inhibitor of these enzymes. Elastase from polymorphonuclear granulocytes interacts with both inhibitors but with different affinities. Compared with the bovine inhibitor, the human inhibitor shows a much lower affinity from this enzyme. Human ITI and its physiological 30-kDa derivative (HI-30) show the same inhibitory properties as HI-14. The differences between human and bovine inhibitors might be explained by a preceding oxidation of Met in vivo of the reactive site residue in position P1 and/or by the influence of the environmental parts connected with this antielastase reactive site region in human ITI or in the active domains thereof.

Alpha-Globulins↗
PubMed1983

[Quantitative exfoliative cytologic studies of the human nasal mucosa].

A new method for collecting nasal secretions yields quantitative cytological results of human nasal secretions. The new results are compared with the conventional methods for obtaining nasal smears by cotton or replica technique. The best staining method is a modified May-Grünwald stain. With the new method, a large area of nasal mucosa is examined contrary to the previous methods where punctual examinations only were possible. Moreover, because the total number of cells can be counted, accurate quantification of individual cell fractions and differentiation of the nasal smears can be effected.

Adult↗