Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The complete amino acid sequence of a basic non-histone protein, H6, isolated from the chromatin of rainbow trout (Salmo gairdnerii) testis cells, has been determined. Protein H6, first described by D. T. Wigle and G. H. Dixon [J. Biol. Chem. 246, 5636--5644 (1971)] was extracted with 5% trichloracetic acid and purified by ion-exchange chromatography on carboxymethyl-cellulose (CM-52). Sequence analysis was performed by automatic Edman degradation of the amino terminus of the intact protein and a series of large fragments derived by cleavage with chymotrypsin, staphylococcal protease and with mild acid to cleave at aspartic acid residues. Protein H6 possesses 69 residues and shows considerable similarities to the 89-residue calf thymus HMG-17 protein previously sequenced [Walker, J. M., Hastings, J. R. B. & Johns, E. W. (1977) Eur. J. Biochem. 76, 461--468]. B. Levy W. and G. H. Dixon [Proc. Natl Acad. Sci. U.S.A. 74, 2810--2814 (1977)] have shown that H6 is selectively solubilized when trout testis nuclei (or chromatin) are digested with DNase I under conditions which preferentially hydrolyze that portion of DNA enriched in transcribed sequences [Levy, W. B. & Dixon, G. H. (1977) Nucleic Acids Res. 4, 883--898]. Recently H6 has been located as a stoichiometric component of a distinct subset of trout testis nucleosomes that are complexed with a core nucleosome comprising 140 base pairs of DNA and the inner histones H2A, H2B, H3 and H4 [Levy, W. B., Connor, W. & Dixon, G. H. (1979) J. Biol. Chem., in the press].
 ...
PMID:The complete amino-acid sequence of a trout-testis non-histone protein, H6, localized in a subset of nucleosomes and its similarity to calf-thymus non-histone proteins HMG-14 and HMG-17. 45 49

Though DNase does not contain any cysteine residues, incubation of the enzyme with 2-nitro-5-thiocyanobenzoic acid in the presence of Ca2+ at pH values above 7.5 results in an irreversible inactivation of the enzyme. The inactivation also occurs when Ca2+ is replaced by Mg2+, but not in their absence. Amino acid analyses after acid hydrolyses of the completely inactivated ant the native enzymes show no significant differences in composition, including tryptophan and half-cystine residues. However, sodium dodecyl sulfate gel electrophoresis indicates enzyme cleavage by the treatment with 2-nitro-5-thiocyanobenzoic acid. This reagent does not inactivate chymotrypsin and lysozyme, and under conditions where bovine DNase is inactivated, does not inactivate other nucleases such as ribonuclease, snake venom phosphodiesterase, and spleen acid DNase. However, it inactivates malt DNase and can, therefore, be considered a specific inhibitor of DNase I. The inactivation kinetics is pseudo-first order, resembling Michaelis-Menten, with an affinity constant of 16.7 mM. It is the cyano group, not the thionitrobenzoic acid of 2-nitro-5-thiocyanobenzoic acid that reacts to form cyano-DNase.
 ...
PMID:Inactivation of bovine pancreatic DNase by 2-nitro-5-thiocyanobenzoic acid. I. A novel inhibitor for DNase I. 48 54

Transcription factor IID from Saccharomyces cerevisiae (YIID) binds the TATA box element present in most RNA polymerase II promoters. In this work, partial proteolysis was used as a biochemical probe of YIID structure. YIID consists of a protease-sensitive amino terminus and a highly stable, protease-resistant carboxy-terminal core. The cleavage sites of the predominant chymotrypsin- and trypsin-derived fragments were mapped to amino acid residues 40 to 41 and 48 to 49, respectively, by amino-terminal peptide sequencing. Removal of the amino terminus resulted in a dramatic increase in the ability of YIID to form a stable complex with DNA during gel electrophoresis mobility shift assays and a two- to fourfold increase in DNA-binding affinity, as assayed by DNase I footprinting analysis. The carboxy-terminal 190-amino-acid core was competent for transcription in vitro and was similar in activity to native YIID. DNA containing a TATA element induced hypersensitive sites in the amino-terminal domain and stabilized the core domain to further proteolytic attack. Native YIID did not bind to a TATA box at 0 degrees C, whereas the carboxy-terminal DNA-binding domain did. These results suggest that YIID undergoes a conformational change upon binding to a TATA box. Southern blotting showed that the carboxy-terminal domain is highly conserved, while the amino-terminal domain diverged rapidly in evolution, even between closely related budding yeasts.
 ...
PMID:Two distinct domains in the yeast transcription factor IID and evidence for a TATA box-induced conformational change. 198 53

Serine proteases, such as alpha-chymotrypsin or elastase, caused an aggregation of rat ascites tumour cell lines, AH-130, AH-109A and YS, in a protein free medium which preserved the cell viability. This aggregation, which was monitored spectrophotometrically, was dependent upon the protease activities and was resistant to treatment with either a calcium chelating reagent (EDTA) or neuraminidase. However, the tumour cell aggregates were redispersed by treatment with deoxyribonuclease I (DNase I). This dispersal effect was dependent upon the DNase activity. A possible relationship between the tumour cell aggregation and development of blood-borne metastasis was studied. An intravenous inoculation in rats of tumour cell aggregates performed by the alpha-chymotrypsin treatment resulted in significantly higher numbers of lung metastatic foci than an injection of single cells. When the re-separated single cells, prepared in vitro by treatment with DNase I following alpha-chymotrypsin treatment, were injected instead of the aggregates, the enhancement of metastasis was reversed. These enhancement and reversal effects were mimicked in vivo by intravenous injections of protease and nuclease following inoculation of a single cell suspension. That is, the number of metastatic foci caused by single cell inoculation followed by an intravenous alpha-chymotrypsin injection, was higher than that in a control group receiving PBS instead of alpha-chymotrypsin. Again, this augmentation was reversed by an injection of DNase I following alpha-chymotrypsin injection. Furthermore, an injection of DNase I alone itself reduced the starting number of metastases resulting from injection of the single tumour cell suspension. These data suggest that the metastatic behaviour of tumour cells may be increased by protease inducible DNA dependent cell aggregation should it occur in the blood stream.
 ...
PMID:Serine protease-induced enhancement of blood-borne metastasis of rat ascites tumour cells and its prevention with deoxyribonuclease. 212 Dec 20

A 20-base pair (bp) conserved sequence present in the 5'-flanking regions of genes highly expressed in the exocrine pancreas forms part of the enhancers of the rat amylase 2A, chymotrypsin B, and elastase I genes. Factor(s) that interact with the conserved DNA sequence of the rat chymotrypsin B gene in vitro have been detected in extracts from acinar cells but not in three other cell lines tested. Transfection experiments suggest that the acinar cell factor(s) recognizing this enhancer core sequence are transcriptional activators. Multimers of a 28-bp sequence located by DNase I protection are capable of activating heterologous promoters in acinar cells. In vitro competition binding and methylation interference analyses indicate protein-DNA interactions at two distinct sites 10 base pairs apart on the DNA. This interaction is identical in extracts from cultured acinar cells as well as from whole pancreas tissue. The presence of two contiguous binding motifs on the same face of the DNA suggests that two (multiple) factors cooperate in the transcriptional regulation of this gene. We term these factors CACCTG pan-1 and TTTCCC pan-1. A factor with the binding specificity of the adenovirus major late transcription factor (MLTF) cross-reacts with the factor CACCTG pan-1 in vitro. However, the distribution of this factor in the various cells does not correlate with the activity of the enhancer core element in vivo. Further, conversion of the chymotrypsin sequence into a consensus MLTF site by three-point mutations abolished enhancer activity in acinar cells. Thus, the MLTF-like factor cannot substitute functionally for the factor CACCTG pan-1 and may act as an inhibitor of chymotrypsin enhancer function.
 ...
PMID:The chymotrypsin enhancer core. Specific factor binding and biological activity. 258 37

A fragment comprising the DNA-binding domain of the human glucocorticoid receptor has been expressed in a functional form in Escherichia coli as a fusion protein with protein A from Staphylococcus aureus. The DNA-binding domain was purified to apparent homogeneity by affinity chromatography on IgG-Sepharose and DNA-cellulose, a purification scheme which does not involve denaturation of the protein at any step. The DNA-binding domain was separated from the protein A part of the fusion protein by domain-specific enzymatic cleavage with chymotrypsin while immobilized on IgG-Sepharose. The recombinant protein has been characterized by amino acid analysis, NH2- and COOH-terminal sequence analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reactivity to iodoacetate and was found to correspond to the primary structure derived from the cDNA sequence. DNase I footprinting showed that the purified recombinant protein bound to the same DNA sequences on the mouse mammary tumor virus long terminal repeat as glucocorticoid receptor purified from rat liver does. About 10 times more recombinant protein, on a molar basis, was needed to obtain the same level of protection. However, the protection of the three different footprints (1.3, 1.4, and 1.5') by the recombinant protein differed greatly from that of the natural receptor, with virtually no protection of footprint 1.4. This indicates cooperative binding of the natural receptor to adjacent footprints, dependent on other regions of the receptor than the DNA-binding domain.
 ...
PMID:High level expression in Escherichia coli of the DNA-binding domain of the glucocorticoid receptor in a functional form utilizing domain-specific cleavage of a fusion protein. 264 5

Transcription factor IIIC2 is required for in vitro transcription of the adenovirus 2 VA1 gene and binds with high affinity to its B-box promoter element which is an 18 bp perfect inverted repeat. Partial proteolysis of TFIIIC2 with chymotrypsin and Staphylococcus aureus V8 protease yielded a species which produced a discrete band in a gel shift assay with about twice the mobility of the undigested complex. Chymotrypsin-digested TFIIIC2 produced a DNase I footprint virtually identical to that of the undigested protein, but the stability of the protein-VA1 DNA complex was drastically reduced and the in vitro transcriptional activity was eliminated. These results indicate that a chymotrypsin-resistant domain of TFIIIC2 binds to the B-box sequence. We speculate that stable binding requires protease sensitive cooperative interactions between TFIIIC2 DNA-binding domains.
 ...
PMID:A DNA-binding domain of human transcription factor IIIC2. 279 26

Activated glucocorticoid receptor (GR) from the human cell line HeLa S3 was purified by differential chromatography on DNA-cellulose followed by DEAE-Sepharose chromatography to 50-60% homogeneity according to sodium dodecyl sulfate gel electrophoresis and densitometric scanning of silver-stained gels. These gels routinely demonstrated a main band of Mr 94,000 (94K band) and two minor bands of Mr 79,000 (79K band) and 39,000 (39K band), respectively. Photoaffinity labeling indicated that the hormone was bound to the 94K and 79K components. In some preparations, a 72K band was observed. Further characterization of the purified receptor by gel permeation chromatography on Sephadex G-200 revealed a receptor complex with a Stokes radius of 5.8 nm. The sedimentation coefficient of the purified receptor was 4.4 Sw. In analogy to the rat hepatic GR, limited proteolysis of the purified GR with trypsin or alpha-chymotrypsin led to degradation of the 94K and 79K components and appearance of 28K and 39K fragments, respectively. In addition, no difference in the protease digestion pattern using Staphylococcus aureus V8 protease was observed. Immunoblotting using a monoclonal antibody raised against the 94K GR from rat liver demonstrated cross-reactivity with the human 94K and 79K proteins from HeLa S3 cells, indicating similar antigenic characteristics between rat and human GR. In our study, five out of nine tested monoclonal antibodies against the rat liver GR cross-reacted with human GR. DNase I and exonuclease III protection experiments demonstrated binding of the purified human GR to specific GR binding regions in mouse mammary tumor virus DNA.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Characterization and sequence-specific binding to mouse mammary tumor virus DNA of purified activated human glucocorticoid receptor. 303 7

Limited proteolysis of G-actin was performed with trypsin and chymotrypsin to compare the binding sites for Gc and DNase. DNase I bound to the N-terminal area corresponding to the major cleavage site on G-actin (residues 62-68) and inhibited proteolysis, but did not bind the 33.5K C-terminal fragment (G-actin33.5) generated. In contrast, Gc did not exert any inhibitory effect upon proteolysis of the intact native G-actin42.0 molecule, although its presence protected G-actin33.5 from further proteolysis. This was shown by gel filtration to be due to the formation of complexes between Gc and G-actin33.5.
 ...
PMID:Gc (vitamin D-binding protein) binds the 33.5 K tryptic fragment of actin. 395 29

A heat-labile, non-dialyzable factor(s) in soluble fractions from porcine, bull, rabbit and cock spermatozoa was found to incorporate the radioactivity of [14C]isoleucine into a 95 degrees C CCl3COOH-insoluble fraction. The incorporation required ATP, Mg2+, casein and 2-mercaptoethanol. Trypsin and alpha-chymotrypsin inhibited the incorporation, while RNase A and DNase I did not. A mixture of 19 amino acids other than isoleucine had no effect on the incorporation. The reaction product was identified as protein. The incorporated moiety was the isoleucyl moiety of isoleucine and it retained a free alpha-amino group in the product protein. Some other characteristics of this incorporation are also described.
 ...
PMID:Incorporation of isoleucine into protein by a soluble fraction from spermatozoa. 398 5


1 2 3 Next >>