Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The conditions were optimized for freezing storage, restoring and further cultivation of hybridoma cells producing antibodies to viral antigens. The effect of density of cellular suspension frozen,concentration of calf embryo serum in cryoprotected medium and mild conditions of the restoring of hybridoma were studied. To restore deeply frozen hybridoma 24 hole plastic panels with a layer of feeding cells of the HEPES and insulin containing medium were used. The fulfilling of these requirements makes possible restoration of intact antibody-producing hybridoma from 10(2)-10(3) frozen cells.
Mol Gen Mikrobiol Virusol 1985 Mar
PMID:[Storage and reconstruction of hybridomas producing monoclonal antibodies against viral antigens]. 384 46

The three-dimensional structure of the head-to-tail connecting region of bacteriophage phi 29 has been studied by analysing two-dimensional, hexagonal ordered aggregates of negatively stained viral necks to a resolution of 2 X 2 nm. These necks are composed of two proteins, p10 and p11; p10 being the connector protein. A 12-folded and a 6-folded axially symmetric domain are present in the specimen. The 12-folded domain is the larger part of the structure; it consists of 12 subunits associated in pairs. These subunits appear to be more closely paired towards the centre, where only six subunits are resolved forming the 6-folded domain. The pairs of subunits present an important twist between the 12-folded and the 6-folded areas. A conical hole is formed at the centre of the structure. This hole is more open at the 12-folded domain than at the level of the possible zone of interaction between p10 and p11, where it is almost closed. Protein p11 is very poorly represented in the reconstruction, probably due to lack of staining. The structure described for the phi 29 neck has many of the attributes expected for an active device involved in bacteriophage DNA encapsidation.
J Mol Biol 1985 May 05
PMID:Three-dimensional reconstruction of bacteriophage phi 29 neck particles at 2 X 2 nm resolution. 400 22

The X-ray structure of a new crystal form of chymotrypsinogen A grown from ethanol/water has been determined at 1.8 A resolution using Patterson search techniques. The crystals are of orthorhombic space group P212121 and contain two molecules in the asymmetric unit. Both independent molecules (referred to as A and B) have been crystallographically refined to a final R value of 0.173 with reflection data to 1.8 A resolution. Owing to different crystal contacts, both independent molecules show at various sites conformational differences, especially in segments 33-38, 142-153 and 215-222. If these three loops are omitted in a comparison, the root-mean-square (r.m.s.) deviation of the main-chain atoms of molecules A and B is 0.32 A. If segments 70-79, 143-152 and 215-221 are omitted, a comparison of either molecule A or molecule B with the chymotrypsinogen model of Freer et al. (1970) reveals an r.m.s. deviation of the alpha-carbon atoms of about 0.7 A. Compared with the active enzyme, four spatially adjacent peptide segments, in particular, are differently organized in the zymogen: the amino-terminal segment 11-19 runs in a rigid but strained conformation along the molecular surface due to the covalent linkage through Cys1; also segment 184-194 is in a rigid unique conformation due to several mutually stabilizing interactions with the amino-terminal segment; segment 216-222, which also lines the specificity pocket, adapts to different crystal contacts and exists in both chymotrypsinogen molecules in different, but defined conformations; in particular, disulfide bridge 191-220, which covalently links both latter segments, has opposite handedness in molecules A and B; finally, the autolysis loop 142 to 153 is organized in a variety of ways and in its terminal part is completely disordered. Thus, the allosteric activation domain (Huber & Bode, 1978) is organized in defined although different conformations in chymotrypsinogen molecules A and B, in contrast to trypsinogen, where all four homologous segments of the activation domain are disordered. This reflects the structural variability and deformability of the activation domain in serine proteinase proenzymes. If the aforementioned peptide segments are omitted, a comparison of our chymotrypsinogen models with gamma-chymotrypsin (Cohen et al., 1981) yields an r.m.s. deviation for alpha-carbon atoms of about 0.5 A. The residues of the "active site triad" are arranged similarly, but the oxyanion hole is lacking in chymotrypsinogen.(ABSTRACT TRUNCATED AT 400 WORDS)
J Mol Biol 1985 Oct 05
PMID:Bovine chymotrypsinogen A X-ray crystal structure analysis and refinement of a new crystal form at 1.8 A resolution. 405 57

Malignant MO4 mouse fibrosarcoma cells were confronted with fragments of hypoblast from stage 4 (Vakaet 1970) blastoderms in different dispositions either permitting or preventing contact of the hypoblast with the tissue culture plastic. Explantation of an MO4 cell aggregate on top of 24 h-old-hypoblast caused retraction of the hypoblast. Contact inhibition of ruffling in hypoblast cells at the inner margin, by MO4 cells migrating radially from the aggregate, prevented closure of the hole brought about by the initial retraction. Disintegration of hypoblast was not observed. Migration of MO4 cells during the first 24 h was faster from an aggregate explanted on top of hypoblast than from an aggregate explanted on tissue culture plastic. Hypoblast fragments explanted on top of confluent layers of MO4 cells attached and spread during the first 12 h. Later, the hypoblast progressively disintegrated. Here, MO4 cells accumulated underneath the hypoblast. We concluded 1) that the hypoblast attracted the MO4 cells by influencing their pattern of migration and 2) that contact with the artificial substrate allowed survival of hypoblast confronting malignant MO4 cells. Ultrastructural analysis suggested that formation of extracellular material played a major role in the interaction between the normal tissue and the malignant cells.
Virchows Arch B Cell Pathol Incl Mol Pathol 1982 Aug
PMID:Interaction of malignant MO4 cells with chick hypoblast in culture. 612 37

The hypoblast (lower layer) was dissected from young chick blastoderms and explanted in vitro, where it formed an epitheloid sheet. Cells from the following malignant lines were explanted on top of the sheet both as aggregates and as cell suspensions: Hu456 human bladder carcinoma, SAOS-2 human osteosarcoma, LICR(LOND)-HN-4 laryngeal carcinoma. The interaction of the malignant cells with the hypoblast was studied by time lapse cinephotography, light microscopy, and transmission electron microscopy. All malignant cells penetrated through the hypoblast, so that a gradually enlarging hole formed in it. Apart from this common pattern of behaviour, the three types of malignant cells differed in their interactions with the hypoblast in the following ways. 1) Both the Hu456 and to a lesser extent the SAOS-2 cells brought about an initial retraction of the hypoblast so that a temporary cell-free space was formed. No such retraction occurred in response to the LICR-(LOND)-HN-4 cells. 2) Each of the three types of malignant cells migrated for some distance beneath the hypoblast, and in this area of underlap, there were differences in the amount and disposition of extracellular material. Thus, there was more extracellular material between the hypoblast and underlying SAOS-2 cells than between the hypoblast and underlying Hu456 cells, whilst there was no extracellular material between the hypoblast and underlying LICR(LOND)-HN-4 cells. Indeed, the hypoblast and LICR(LOND)-HN-4 cells often shared desmosomes. 3) When explanted as aggregates on hypoblast Hu456 and SAOS-2 cells left the corona and migrated as solitary cells underneath the hypoblast in contrast with control aggregates explanted on plastic. These cells which had migrated beneath the hypoblast were flatter than their corresponding control cells which had spread on the plastic substrate. The flatter cells appeared to have been using the extracellular materials as a substrate, rather than the plastic. Such differences in the migratory behaviour between experimental and control cultures were not observed with LICR(LOND)-HN-4 cells.
Virchows Arch B Cell Pathol Incl Mol Pathol 1983
PMID:Interaction of three human malignant cell lines with chick hypoblast in culture. 613 8

The protein S100 markedly increases the net intake of GABA across the plasma membrane of Deiters' neurons which have GABA receptors on their surfaces. This membrane function of S100 was found by using a new microtechnique. Plasma membranes of such cells have been freshly prepared by freehand microsurgery and are tightly fixed over a 30-micrometers phi hole between two compartments of a microchamber containing 2.0 mM GABA in 7.5 microliters and 0.2 mM GABA in 75 microliters, respectively. The transport of GABA has been determined after incubation of the membrane for from 30 sec to 10 min at 29 degrees C. GABA is transported at a rate of 145 ng in 3 min over a 700-micrometers2 membrane area. S100 in its calcium form reacts with the membrane and increases GABA transport by 20% which is ATP dependent and inhibited by ouabain and ruthenium red. The kinetics of the transport furthermore prove that GABA transport across the plasma membrane is an active process.
Cell Mol Neurobiol 1981 Sep
PMID:The effect of S100 protein on the plasma membrane function of neurons. 628 28

The photoinduced electron transfer at low temperatures in phospholipide membranes (liposomes) containing chlorophyll and 3 X 10-docsilpalmitate has been investigated. The reduction of 3 X 10-docsilpalmitate was estimated by ESR spectrometry. When diffusion movement of the molecules in membranes was blocked by low temperatures the photoinduced electron transfer has been found. The mechanism of these phenomena were analyzed on the base of donor-acceptor interaction through sigma bonds in hydrocarbon bridged donor-acceptor complexes. The separation of charges in these complexes is regarded as occurs by the migration of a hole along the hydrocarbon system. An approximate estimate of the charge mobility in the saturated hydrocarbon side chain of chlorophyll and activation energy of these movement was obtained.
Mol Biol (Mosk)
PMID:[Photoinduced electron transfer through the hydrocarbon zone of membranes at low temperatures]. 631 19

Interaction of oligoadenylic acids (pA) n, n = 3 to 6, with the protein of tobacco mosaic virus has been studied by methods of equilibrium dialysis, gel filtration, and precipitation of the complex by centrifugation. It has been found that oligo(A) forms specific complexes with virus-like helical protein aggregates (HPA), but does not interact neither with double disks nor other small protein aggregates. Interaction becomes stronger when pH and/or ionic strength are decreased. The binding of (pA)3 to HPA decreases with temperature, whereas the binding of longer oligonucleotides increases. The binding constants for the interaction of (pA)3 with HPA in 0,1 M acetate pH 5.50 have been found to be equal 510 +/- 70 at 30 degrees C and 1960 +/- 250 at 0 degrees C. In the case of (pA)3 the binding equilibrium is reached within minutes at T greater than or equal to 20 degrees C; 15 h is needed for the same at 0 degrees C. The binding of oligonucleotides containing four or more residues proceeds at a much lower rate. For instance, in the case of (pA)5 the equilibrium is not reached even within 200 hours at 0 degrees C or 48 hours at 30 degrees C. Two possible mechanisms of interaction are discussed: (1) direct interaction of oligonucleotides with the inner part of protein aggregate through the central hole of the particle due to the fluctuational opening of the V-helices (2) binding of oligonucleotides on the end surfaces of HPA followed by their redistribution along the particle due to the end-to-end association and disruption of particles. A hypothesis concerning the phasing of RNA in the initiation complex is advanced making use of the data of J.J. Steckert and T. M. Schuster.
Mol Biol (Mosk)
PMID:[Interaction of oligoadenylic acids with repolymerized protein of tobacco mosaic virus]. 647 63

Hydrodynamic calculations lead to the conclusion that chymotryptic (or ethylenediaminetetraacetic acid) myosin S1 in solution (hydrated), at 1-5 degrees C, can be modeled as a prolate ellipsoid, with an axial ratio lying between p = 1.0 and 2.5 (major axis between 100.5 A, for p = 1.0, and 162.5 A, for p = 2.5). The degree of hydration is considerable (1.24 g/g for p = 2.5 and 2.02 g/g for p = 1.0). The dehydrated myosin head is pear-shaped under the electron microscope, and its narrowest part is located near the junction with the tail [Elliott, A., & Offer, G. (1978) J. Mol. Biol. 123, 505-519]. Mendelson & Kretzschmar [Mendelson, R. A., & Kretzschmar, K.M. (1980) Biochemistry 19, 4103-4108] have shown that the pear-shaped molecule does not predict the experimental X-ray scattering curve. Nor is this model able to predict the hydrodynamic values. The three-dimensional model for S1 used by Mendelson and Kretzschmar gives a rather good fit to the experimental X-ray scattering curve, but it does not predict the hydrodynamic values. In order to try to reconcile the three models and to fit the X-ray scattering curve and the hydrodynamic data, we suggest that, in solution, the S1 monomer has the shape of a prolate ellipsoid and that an inclusion of bound water exists at one extremity of the protein. The rest of bound water surrounds the protein. As first approximation, the dry protein and the hole are assumed to have the same shape as the hydrated molecule (prolate ellipsoid; p).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Reinvestigation of the shape and state of hydration of the skeletal myosin subfragment 1 monomer in solution. 663 38

The method of hole-burning in absorption spectra at helium temperatures has been applied to the study of primary photoprocesses in photosystem II (PS2) of Chlamydomonas reinhardii mutant strains 420/7 and N-154. The former is enriched in PS2 reaction centers (the chlorophyll a/P680 ratio is about of 50--70) and the latter presumably lacks the pheophytin molecule which is the primary electron acceptor in PS2. For the strain 420/7 samples with ferricyanide addition two types of holes have been observed differing in their width and spectral region of burning. One type could be burned in the region of 678--682 nm (P680 is responsible for burning) and another one -- in the region of 682--688 nm (pheophytin is responsible). The excited states relaxation times evaluated from the hole widths are 3,8 +/- 0,8 ps for P680 and 9,8 +/- 1.5 ps for pheophytin. The new mechanism of PS2 operating has been proposed in which photoexcited phenophytin molecule functions as a primary electron donor. In the case of N-154 strain the only type of holes has been observed for which P680 is responsible. The excited state relaxation time of the latter evaluated from the hole width is 10 +/- 2 ps.
Mol Biol (Mosk)
PMID:[Study of primary photoprocesses in photosystem II of Chlamydomonas mutant strains by hole-burning spectroscopy]. 709 59


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