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)

30-S dynein ATPase from Tetrahymena cilia was digested with trypsin (dynein: trypsin = 20:1, by weight) at 25 degrees C for 20 min, resulting in the release of a 12-S fragment possessing ATPase activity. The 12-S ATPase fraction obtained by sucrose gradient centrifugation contained several polypeptide chains as indicated by SDS gel electrophoresis. The largest chain was smaller than the subunit of 30-S dynein and almost the same size as 14-S dynein. On the other hand, when 14-S dynein was digested in a similar manner, its sedimentation value changed from 14 to 12 S, but the peak of ATPase activity was retained at 14 S, suggesting differences in amino acid sequences between the 30 and 14-S dyneins. When the time course of tryptic digestion of 30-S dynein was investigated in a trypsin:dynein ratio of 1:200, discrete fragmentation took place, producing an intermediate fragment of 24 S and the 12-S fragment. The 24-S fragment recombined with outer fibers to some extent, while the 12-S fragment lacked this ability. However, the 12-S fragment was somewhat stimulated to recombine with outer fibers in the presence of other components involved in the trypsin digest. The enzymatic characteristics of the 12-S fraction were different from those of 30-S dynein, especially the activity dependence on pH showing a typical bell-shaped curve.
 ...
PMID:Tryptic fragmentation of 30-S dynein from Tetrahymena cilia. 14 Jul 5

A partial purification of epidermal G2 chalone from crude epidermal cell extracts from hairless mice is described. The procedure involved the sequential use of ammonium sulphate precipitation, affinity chromatography and gel filtration. Mitosis-inhibiting activity at each stage in the purification was tested in an in vitro assay system employing human epidermoid carcinoma cells in exponential growth phase and Colcemid (Ciba) for arresting mitoses. This assay system is much more rapid and convenient than conventional in vivo systems. By the procedure described, a 10,000-fold material purification of the active component has been obtained. This corresponds to a 3,000-fold purification measured by protein content, and a 300-fold increase in mitosis-inhibiting activity per unit we;ght. The active component is acidic, contains sugar residues and has gel chromatographic properties characteristic of a substance with molecular weight of approximately 20,000. On SDS polyacrylamide gel electrophoresis, however, three weak bands were found. The active component is resistant to trypsin and protease and stable between pH 6.0 and 8.5. It is easily inactivated at pH values below 6.0. At the present stage of purification, several components other than the active one still remain in our material and further purification steps must be eventually employed.
 ...
PMID:Partial purification of epidermal G2 chalone. 14 51

A method for primary culture of ovine myometrial cells is described. After dissection, myometrium of ewe uteri was digested in trypsin and collagenase. The cells were preplated for 1 h at 37 degrees C. The non-attached cells were grown in appropriate medium supplemented with 2% fetal calf serum. They had a doubling time of 3 days, reached confluency at 10 days and did not exhibit contact inhibition. Cultures were maintained up to 22 days. Characterization of the cells was achieved by electron microscopy, analysis of myosin in cell extracts and assessment of hormone sensitivity. The cells were found to contain myofilaments, characteristic of smooth muscle. A high content of myosin (6--13%) was demonstrated on SDS-polyacrylamide gel electrophoresis: this was confirmed by ATPase activity assay. Cells responded to estradiol stimulation by increased protein synthesis, and bound [3H]estradiol in a specific and saturable way. These results suggest that myometrial cells grown in primary culture should provide a useful model for studying the hormonal control of contractile protein synthesis.
 ...
PMID:Myometrial cells in primary culture: characterization and hormonal profile. 15 21

Intracytoplasmic A particles were analyzed by immunodiffusion and sodium dodecyl sulfate--polyacrylamide gel electrophoresis (SDS--PAGE) before and after enzymatic cleavage with trypsin. A common antigen in A particles was detected by antisera prepared against purified intracytoplasmic A particles, purified mouse mammary tumor virus (MMTV), and a purified MMTV core polypeptide (p28). Despite this correlation, no SDS--polyacrylamide band migrating at p28 was observed in purified intracytoplasmic A particles. However, after incubation with trypsin, A particles subjected to SDS--PAGE produced only two polypeptide bands. They were observed at p28 and p15-10. Ouchterlony analysis of the trypsin-cleaved A particles revealed no alteration in the antigenicity of the particles. These results suggested that some structural components of intracytoplasmic A particles are polypeptide precursors of MMTV core proteins.
 ...
PMID:Mouse mammary tumor virus polypeptide precursors in intracytoplasmic A particles. 16 80

In addition to the four major polypeptides VP1 and VP4, foot-and-mouth disease virus particles contain two minor polypeptides, mol. wt. 40 X 10(3) (P40) and 52 X 10(3) (P52). Extensive purification procedures failed to remove these minor polypeptides from the virus particles. Polypeptide P40 co-electrophoresed in SDS-polyacrylamide gels with VP0, the probable precursor of VP2 and VP4 and was inaccessible to iodination in situ. The second minor polypeptide, P52, co-electrophoresed with the virus infection associated (VIA) antigen found in large amounts in harvests of the virus grown in BHK 21 cells. Polypeptide P52 was shown to be located near the surface of the virus particle by iodination experiments and by its removal on incubating the particles with trypsin or chymotrypsin. Pactamycin mapping showed that this polypeptide was not a precursor of the structural polypeptides. About one copy of P52 and 4 copies of P40 were found in the virus particles sedimenting at 146S. However a larger number of copies was found in those virus particles sedimenting faster than the 146S peak.
 ...
PMID:Characterization of the minor polypeptides in the foot-and-mouth disease particle. 17 28

The radioactive 125I-labelled neurotoxin of C. botulinum type A, when incubated with rat brain homogenate, is bound selectively to the synaptosome fraction. Intact toxin was liberated from the synaptosome fraction by treatment with Triton X-100, SDS, trypsin or neuraminidase.
 ...
PMID:Binding of botulinum neurotoxin to the synaptosome fraction of rat brain. 18 22

Delta toxin, a hemolytic exocellular protein excreted by C. perfringens type C has been purified to homogeneity, assessed by polyacrylamide disc gel electrophoresis. Purification steps involved successively calcium phosphate gel formation in culture supernatant fluid, salting-out of unadsorbed material by ammonium sulfate to 50 % saturation, isoelectric focusing and gel filtration on Sephadex G75. Purified toxin appears as a basic protein occuring in two forms with isoelectric points of 8.8 and 9.4 as disclosed by isoelectric focusing. Molecular weight estimated by SDS-polyacrylamide disc gel electrophoresis was found to be close to 42,000 for the two forms. The lytic activity of delta toxin is inhibited by Ca++ and EDTA. The toxin is activated by short-term treatment with low concentration of trypsin.
 ...
PMID:[Purification and some properties of "Clostridium perfringens" delta toxin (author's transl)]. 19 18

The apoprotein (apoB) of low density lipoprotein (LDL) is reported to be a large polypeptide, and it is proposed that there are two similar-sized subunit proteins in LDL (Smith, Dawson, and Tanford. 1972. J. Biol. Chem. 247: 3376-3381.). When apoB is isolated under conditions that minimize artifactual proteolysis, only a single, large molecular weight protein appears on polyacrylamide gel electrophoresis in SDS. To investigate the organization of apoB as it exists within native LDL, limited proteolysis with trypsin has been used as a structural probe. Tryptic digestion for 1 hr at pH 7.6 with enzyme-to-protein ratios of 1:100 and 1:5 results in the liberation of approximately 10% and 30% of apoB as smaller, water-soluble peptides. These peptides may be separated from the partially digested but still intact tryptic core (T-core) of the lipoprotein by chromatography on Sephadex G-75. Repeatedly, the 1:5 T-core of native LDL is found to contain a family of polypeptides of 14,000-100,000 molecular weight. Although they have lost significant quantities of apoprotein, these T-cores sustain an appearance of homogeneity, as studied by analytical ultracentrifugation. Their measured molecular weights do not differ appreciably from those of the native LDL, and the carbohydrate content of the 1:5 tryptic T-core of LDL is similar to that of the native LDL. In normolipemic individuals, LDL generally exists in a monodisperse state, but, in different individuals, monodisperse LDL may range in molecular weight from 2.4 to 3.9 x 10(6). Limited tryptic digestions were used to probe the organization of apoB in these different molecular weight LDL. As assayed by SDS-acrylamide gel electrophoresis of the larger polypeptides and fingerprinting of the smaller released peptides, those regions of LDL exposed to trypsin digestion are identical in monodisperse LDL of 2.5 and 3.4 x 10(6) molecular weight. Thus, the different quantities of lipid bound in these various LDL must interact with apoB so that the same regions of the apoprotein are exposed to the action of trypsin in these different molecular weight lipoproteins.
 ...
PMID:Proteolytic digestion in the elucidation of the structure of low density lipoprotein. 20 2

The serological characterization of virus isolates from verrucae vulgares and plantar warts revealed that HPV 1 and HPV 4 are present in about 50% of these warts with HPV 1 being more prevalent, especially in plantar warts. Parallel to the high incidence of HPV 1 infections, about 50% of non-selected young adults contained antibodies against HPV 1. Only HPV 4 particles, however, reacted with serum from a patient with epidermodysplasia verruciformis when tested by immuno-electron microscopy. An examination of HPV 1 proteins indicated that the major structural proteins VP2 and VP3 are trypsin sensitive. Tryptic degradation leads to distinct polypeptides with molecular weights between 37,000 and 23,000 which may be correlated to minor protein components of HPV 1 preparations. HPV 1 histone-like proteins, which co-migrate with purified cellular histones in SDS gel electrophoresis were analyzed in an acetic acid urea system. It was shown that H3- and H4-like proteins differ from cellular histones. The reason for this difference and its meaning are discussed.
 ...
PMID:Characterization of proteins of human papilloma viruses (HPV) and antibody response to HPV 1. 21 77

The structural polypeptides of egg grown mumps virus were analysed by SDS-polyacrylamide-slab-gel electrophoresis. Mumps virions contained eight major polypeptides with mol. wt. of 75, 73, 71, 61, 47, 44, 42 and 40 X 10(3). The 75 K and 61 K polypeptides were glycosylated. In virions treated with pronase and trypsin, the 75 K glycoprotein was removed more readily from the virus than the 61 K glycoprotein. The gradual removal of the 75 K glycoprotein was paralleled by a decrease of haemagglutinating activity. The large glycoprotein was cleaved into a 40 K glycoprotein by trypsin treatment. Pronase and trypsin treatment also removed the smallest 40 K non-glycosylated polypeptide. Thus this polypeptide appears to be located on the outside of the virion and probably represents a cleavage product of the large glycoprotein. Treatment of virions with 2% Triton-X 100 under alkaline conditions in the absence or presence of 2 M-KCl solubilized the two glycoproteins and a fraction of the 71 and 44 K polypeptides, but not the 73 and 47 K polypeptides. The two smallest polypeptides were solubilized by treatment with 2% Triton X-100 in the presence of 2 M-KCl. Since the 40 K polypeptide was interpreted to represent a cleavage product of the large surface glycoprotein the 42 K polypeptide was proposed to represent the membrane protein of mumps virus. The 44 K polypeptide co-migrated with Vero cell actin. The nature of the 47 K polypeptide could not be determined, but it is probably located in the central part of the virus. The 73 K polypeptide and in some experiments also the 71 K polypeptide were found in purified nucleocapsid preparations. It is concluded that mumps virus has a general polypeptide composition similar to other paramyxoviruses. However, the molecular weights of the different polypeptides of mumps virus differ markedly from the corresponding polypeptides in Newcastle disease virus and Sendai virus.
 ...
PMID:Structural polypeptides of mumps virus. 21 49


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>