Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cells of Escherichia coli treated with lysozyme and Brij-58 become permeable to proteins, but do not release their DNA. I incubated permeable cells with an endonuclease that produces single-strand breaks in DNA-containing pyrimidine dimers. The enzyme entered the permeable cells, and, if they had been irradiated with ultraviolet light, caused breaks in their DNA. The frequency of breaks was estimated from the sedimentation pattern of the DNA in alkaline sucrose gradients. The procedure is sensitive enough to detect the dimers produced by a dose of 10 erg/mm(2) at 254 nm, or about 50 dimers per E. coli genome. This method exemplifies and extends the use of permeabilized cells for examining biological processes at the molecular level.
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PMID:A method for detecting pyrimidine dimers in the DNA of bacteria irradiated with low doses of ultraviolet light. 458 22

The purpose of this paper is to present a new approach to the study of mechanical properties of globular proteins and to summarize some of our results. The approach is based on the analysis of mechanical, viscoelastic properties of a protein monocrystal which is used as a probe of mechanical properties of a protein molecule. As a first rough approximation a protein molecule can be considered as a material resembling molecular crystals and glass-like polymers with the Young's modulus E = 2 - 10 GN . m-2. More detailed information concerning the anisotropy of elasticity and that of inhibitor effect strongly suggests that the lysozyme molecule is a construction having a special hinge-bending degree of freedom. The force constant estimated from our data for this degree of freedom is (0,4-1) . 10(13) erg . rad-2 . mol-1.
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PMID:[Mechanical properties of globular proteins]. 687 32

By using a supersaturation gradient along a protein solution contained in a glass capillary tube, we modified the classical double pulse technique, thus substantially accelerating the procedure of measurement of nucleation parameters. Data for the number of crystal nuclei, n vs nucleation time, t, were obtained for hen-egg-white lysozyme, chosen as a model because of the availability of reliable solubility data in the literature. The stationary nucleation rate and the nucleation time lag have been measured. Quantitative data for the work required for nucleus formation (A(k) = 4.3 x 10 (-1)3 erg) and the size of the critical cluster (three molecules) were also obtained. Besides, it was observed that Ostwald ripening seems to play an important role for nucleation times longer than 150 min. Using the same technique, semi-quantitative investigations were performed with porcine pancreatic trypsin.
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PMID:Nucleation of protein crystals in a wide continuous supersaturation gradient. 1235 71