Showing papers by "Centre for Cellular and Molecular Biology published in 1984"
TL;DR: The availability of the purified TATA from a rat tumor provides, for the first time, a handle for the identification and further characterization of such molecular species.
Abstract: A unique cell surface antigen of a chemically induced rat hepatoma (Zajdela Ascitic Hepatoma, ZAH) has been identified serologically and purified to apparent homogeneity. ZAH cells, when injected subcutaneously or intradermally into syngeneic hosts, elicit a weak humoral antibody response directed against a single cell surface antigen. In spite of prolonged and extensive immunization, the syngeneic anti-tumor antibodies are solely of the IgM class. Antisera from such immunized animals lyse tumor cells in the presence of complement. These observations were utilized in developing methods for the identification and purification of the antigen. It was observed that administration of purified preparations of this antigen confers ZAH-specific tumor immunity in syngeneic animals. Hence the serologically unique antigen is also the tumor-associated transplantation antigen (TATA) of this tumor. This is the first reported purification of a TATA from a rat tumor. There is considerable earlier evidence for the existence of tumor-associated factors which elicit a strong suppressor-cell response in tumor-bearing rats. The availability of the purified TATA from a rat tumor provides, for the first time, a handle for the identification and further characterization of such molecular species.
139 citations
TL;DR: Noninvasive photoacoustic spectroscopy was used to study the malaria parasites Plasmodium chabaudi and Plas modium berghei, their pigment, and ferriprotoporphyrin IX, which is a by-product of the hemoglobin that the parasite ingests.
Abstract: Noninvasive photoacoustic spectroscopy was used to study the malaria parasites Plasmodium chabaudi and Plasmodium berghei, their pigment, and ferriprotoporphyrin IX, which is a by-product of the hemoglobin that the parasite ingests. The results indicate that the pigment consists of ferriprotophorphyrin self-aggregates and a noncovalent complex of ferriprotoporphyrin and protein. Spectra of chloroquine-treated parasites reveal in situ interaction between the drug and ferriprotoporphyrin. Chloroquine-resistant parasites, readily distinguishable by this method, appear to degrade hemoglobin only partially.
48 citations
TL;DR: It has been shown that bovine ampullae, gland vesicularis and corpus prostate, but not testes and epididymis, contain seminalplasmin.
Abstract: Using immunoglobulin G (IgG)- antibodies raised against highly purified, homogenous seminalplasmin (SPLN), an antimicrobial protein of bovine seminal plasma, it has been shown that bovine ampullae, gland vesicularis and corpus prostate, but not testes and epididymis, contain SPLN. The content as estimated by radioimmunoassay employing [ 125 I]SPLN was: ampullae. 267±13: gland vesicularis, 275±14 and corpus prostate, 445 ±22 μg per gram wet weight of the tissue. SPLN, as characterised by high performance liquid chromatography and in vivo inhibition of RNA synthesis in E. coli, was isolated from gland vesicularis. The SPLN content of bovine seminal plasma was shown to be 1%. A chymotryptic peptide of SPLN comprising residues 1-13 from the amino terminus was found to compete with [ 125 I]SPLN for binding to anti-SPLN IgG.
22 citations
TL;DR: This work has shown that seminal plasma contains the combined secretion of all the male accessory sex glands and is of great physiological significance since it serves as the carrier of sperm to the female reproductive tract; it also influences sperm motility and the acrosome reaction.
20 citations
TL;DR: Peptide fragments corresponding to the signal sequence of chicken lysozyme, labelled with the fluorescent 5‐dimethylaminoaphthalene‐1‐sulfonyl(dansyl) group have been synthesized to study the interaction of signal sequence fragments with liposomes.
13 citations
01 Jan 1984
TL;DR: NMR results reveal that these ‘water penetration probes’ are located largely in the headgroup region of micelles, and would thus be expected to monitor the polarity and water content of this region rather than those of the micellar interior.
Abstract: The sites of solubilization of some classes of ‘water penetration probes’ in micelles have been studied. These probes, which invariably contain polar or aromatic groups in them, are shown to be inherently interfacially active. The effect of such an activity is seen to be enhanced when the probes are solubilized in systems of large surface area-to-volume ratios such as amphiphile aggregates. NMR results reveal that these ‘water penetration probes’ are located largely in the headgroup region of micelles. They would thus be expected to monitor the polarity and water content of this region rather than those of the micellar interior. Thus, studies using such probes do not necessarily prove the existence of water inside micelles and related assemblies.
8 citations
TL;DR: It is argued that DNA may not contain information for certain types of organisation found in living cells, and may be necessary for a cell to possess the “non-DNA-controlled” organisation for performance of its minimum functions.
Abstract: On the basis of evidence that several low-molecular-weight substances as well as enzymes are compartmentalised within the socalled soluble phase of the cell, and other considerations, it is argued that DNA may not contain information for certain types of organisation found in living cells. It may be necessary for a cell to possess the “non-DNA-controlled” organisation for performance of its minimum functions; such organisation would then also serve as a “template” for its appearance in the daughter cell. The problem of transition from chemical to biological evolution (that is, the formation of the “first cell”) may be essentially the problem of emergence of such intracellular organisation for which information may not reside in DNA. Two possible mechanisms through which this may have happened are stated.
4 citations
TL;DR: An integral, strong RNAase-A-like ribonucleolytic activity is shown in the plasma and outer acrosomal membranes of bovine spermatozoa and a part of this activity is extractable by salt or detergent.
Abstract: We show here the presence of an integral, strong RNAase-A-like ribonucleolytic activity in the plasma and outer acrosomal membranes of bovine spermatozoa. A part of this activity is extractable by salt or detergent.
1 citations
TL;DR: Age-related changes in the primary structure of alcohol dehydrogenase (ADH) from three different strains of Drosophila melanogaster have been investigated by tryptic peptide analysis and it is demonstrated that there are no significant differences between the ADH tryptic Peptide profiles of young and old flies.
1 citations
TL;DR: The program is written for the Apple II microcomputer and is capable of calculating the sedimentation coefficient at an infinite dilution from the data collected at varying concentrations.
DOI•
01 May 1984TL;DR: In this paper, the intramolecular co-ordination of the quinone and the cooperativity in binding of an external ligand was established, based on the movement of the metal ion into the porphyrin plane.
Abstract: The strategies for the synthesis of covalently linked, flexible and rigid quinoneporphyrin complexes are described. Several anomalous chemical reactivities were observed in the quinone-capped porphyrins which may be attributed to the proximity of quinone and porphyrin moieties. Previous investigations by1Hnmr spectroscopy have demonstrated that the metal ion in capped metalloporphyrins is 5 co-ordinate, bound intramolecularly to quinone carbonyls and can accept a sixth ligand from the unhindered side. Here, additional evidence from13CNMR spectroscopy is presented to support the intramolecular co-ordination of the quinone and establish the cooperativity in binding of an external ligand; this process involves the movement of the metal ion into the porphyrin plane, pulling the quinone chromophore closer to the porphyrin. Electrochemical results reveal that the quinone in capped metalloporphyrins are better electron acceptors than simple quinones. The intramolecular quinone-porphyrin complexes promise to be potential model compounds to demonstrate the primary photosynthetic eventin vitro.