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Biomedical subjects

F P Milanovich

Publications and source records attributed to F P Milanovich.

6 recordsLinked to original sources

Field-deployable sniffer for 2,4-dinitrotoluene detection.

A field-deployable instrument has been developed to detect low-level 2,4-dinitrotoluene (2,4-DNT) vapors. The system is based on previously developed artificial nose technology and employs an array of sensory materials attached to the distal tips of an optical fiber bundle. Both semiselective and nonspecific, cross-reactive sensors were employed. Each sensor within the array responds differentially to vapor exposure so the array's fluorescence response patterns are unique for each analyte. The instrument is computationally "trained" to discriminate target response patterns from nontarget and background environments. This detection system has been applied to detect 2,4-DNT, an analyte commonly detected on the soil surface above buried 2,4,6-trinitrotoluene (TNT) land mines, in spiked soil and aqueous and ground samples. The system has been characterized and demonstrated the ability to detect 120 ppb 2,4-DNT vapor in blind (unknown) humidified samples during a supervised field test.

Carcinogens↗

Evidence of novel secondary structure in DNA-bound protamine is revealed by Raman spectroscopy.

Raman spectroscopy studies of protamine-DNA complexes are reported for samples in the solid state at 98% relative humidity. Previous reports utilizing other physical techniques have indicated the presence of B-form DNA in protamine-DNA complexes. The present Raman data support the assignment of a modified B-form which is characterized by appreciable unstacking of the bases. The quality of the present spectra has made it possible, for the first time, to obtain the Raman spectrum of DNA-bound protamine by digital spectral subtraction. The difference spectrum indicates that protamine adopts an unusual secondary structure upon binding to DNA. A dominant amide I band is observed at 1683 cm-1 which is indicative of neither an alpha-helix or beta-sheet conformation. An amide I band at this position has been associated with the 1-->3 hydrogen bond that occurs within a gamma-turn [Bandekar, J., & Krimm, S. (1985) Int. J. Pept. Protein Res. 26, 158-165]. On the basis of this assignment, as well as preliminary results obtained by computer modeling, we propose a new model for the secondary structure of DNA-bound protamine that is rich in 1-->3 hydrogen bonding. Spectral data demonstrate that this structure is absent in protamine molecules in solution. Analyses of spectra of polyarginine-DNA complexes suggest that polyarginine, although similar to protamine in primary structure, assumes a conformation when bound to DNA that is distinct from that adopted by protamine.

Amino Acid Sequence↗

Raman spectroscopic investigations of sarcoplasmic reticulum membranes.

Raman spectra are presented for sarcoplasmic reticulum membranes. Interpretation of the 1000-1130 cm-1 region of the spectrum indicates that the sarcoplasmic reticulum membrane may be more fluid than erythrocyte membranes that have been examined by the I portion of the membrane spectrum with a strong 1658 cm-1 band characteristic of C=C stretching in hydrocarbon side chains exhibiting cis conformation. This band is unaltered in intensity and position in H2O and in 2H2O thus obscuring amide I protein conformation. Of particular interest is the appearance of strong, resonantly enhanced bands at 1160 and 1527 cm-1 attributable to membrane-associated carotenoids.

Animals↗