Griffith, O. Hayes H.

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Biological Photocathodes
(Proceedings of the National Academy of Sciences, 1989-03) Griffith, O. H.; Habliston, D. L.; Birrell, G. B.; Skoczylas, W. P.; Hedberg, K. K.
Biological surfaces emit electrons when subjected to UV light. This emission is increased greatly after exposure to cesium vapor. Increases from 2 to 3 orders of magnitude are observed, depending on the biochemicals present. Heme and chlorophyll exhibit unusually high photoemission currents, which are increased further after cesiation. Photoemission from proteins and lipids is much less but also is increased by exposure to cesium. The formation of photocathodes with cesium greatly increases the practical magnifications attainable in photoelectron microscopy of organic and biological specimens. Photoelectron micrographs taken at magnifications ;;;: x 100,000 of chlorophyll-rich thylakoid membranes and of colloidal gold-labeled cytoskeleton preparations of cultured epithelial cells demonstrate the improvement in magnification. The selectivity and stability of the photocathodes suggest the possibility of detecting chromophore binding proteins in membranes and the design of photoelectron labels for tagging specific sites on biological surfaces.
Open Access
Electron optical benches for in-line and branched systems. A new bench designed for mirror-based aberration correction and low energy electron microscopy
(Review of Scientific Instruments, 1994-10) Skoczylas, W. P.; Rempfer, G. F.; Griffith, O. H.
A review of electron optical bench literature is presented, and the designs of two optical benches used by the authors are described. One bench was designed for testing individual electrostatic electron lenses and in-line optical systems, for example, emission electron microscopes and transmission electron microscopes. It has been in operation for many years. The second electron optical bench is new. It is a branched system designed for several purposes: to study correction of spherical and chromatic aberration with an electron mirror, and to gain experience with low energy electron microscopy (LEEM) optics. The alignment of the electron optical support structure is independent of the vacuum housing, and the bench is designed to be operated either horizontally or vertically. As a demonstration of the performance of the new bench in the horizontal mode, a test pattern on a silicon surface was imaged with LEEM optics.
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Electron spin resonance and electronic structure of the RCHOR' ether radical
(Journal of Chemical Physics, 1965-04-15) Griffith, O. H.
Single crystals of inclusion compounds formed between urea and aseries of aliphatic ethers were xirradi ated and studied by electron spin resonance. The stable, x-ray-produced free radicals were all of the general type RCHOR'. The approximate value for the spin density on the carbon atom is 0.70±0.10. The unpaired spm distnbution is discussed in terms of the Hiickel and approximate configuration interaction ^--electron molecular orbital models and the valence bond method. The theoretical spin distributions are found tobe in qualitative agreement with the experimental spin distribution.
Open Access
Electron spin resonance and molecular motion of the RCH2CHCOOR' radicals in X‑irradiated ester‑urea inclusion compounds
(Journal of Chemical Physics, 1964-08-15) Griffith, O. H.
Single crystals of the inclusion compounds formed between long-chain alkyl esters and urea were x irradi ated at room temperature, and the free radicals produced were investigated by electron spin resonance. The 11 esters studied were diethyl adipate and the methyl, ethyl, hexyl, and octyl esters of monocarboxylic acids. The long-lived free radicals observed in all of these compounds are of the type RCHaCHCOOR'. These are ir-electron radicals with the unpaired electron largely localized on one carbon 2p orbital. The coupling constants of the alcohol protons (R') were resolved in the spectra of several radicals and the values ranged from 3 to 6 Mc/sec. The ester radicals undergo motion in the tubular cavities formed by the urea molecules of the crystal, and this affects the magnitudes of the proton coupling constants. The de pendence of the a-and /3-proton coupling constants on this motion is briefly considered. From the ethyl heptanoate radical ESR data, recorded over the range of 352° to 7°±3°K, and from the room-temperature ESR data of all eleven ester radicals, information is obtained regarding the motions and orientations of the ester radicals. In addition, two carboxylic-acid-urea inclusion compounds were investigated, and the orientations and motions of the well-known radicals produced in these systems (RCH2CHCOOH) are compared to those of the ester radicals. Approximate equations are given which relate the observed a-proton coupling constants and spectroscopic splitting factors to the diagonal elements of the a-proton tensors and g tensors of all radicals investigated.
Open Access
Electron spin resonance of biological membranes ‑ Spin‑labeled lipids and proteins
(Magnetic Resonance Review, 1988) Volwerk, J. J.; Griffith, O. H.
Open Access
Electron spin resonance of free radicals in perhydrotriphenylene inclusion compounds
(Proceedings of the National Academy of Sciences, 1965-11) Griffith, O. H.
Open Access
Electron spin resonance of oriented RCHSR' sulfide radicals
(Journal of Chemical Physics, 1967-07-15) Griffith, O. H.; Mallon, M. H.
Single crystals of the di-n-hexyl sulfide-urea and diethyl s~lfide--~rea inclusion comi;>ounds were x irradiated at 77°K and the long-lived free radicals produced were mvest1gated by electron spm resonance. The free radicals observed in both crystals were of the type RCHSR'. The value for the spin density on the carbon atom is 0.74±0.07 . The unpaired spin distribution is discussed in terms of simple molecularorbital models.
Open Access
Electron spin resonance of RCHCOR'radicals in X‑irradiated ketone‑urea inclusion compounds
(Journal of Chemical Physics, 1965-04-15) Griffith, O. H.
Single crystals of six inclusion compounds formed between aliphatic ketones and urea were x irradiated at room temperature, and the free radicals produced were investigated by electron spin resonance. The six ketones investigated were 2-nonanone, 6-undecanone, 3-tetradecanone, 2-undecanone, 2-dodecanone, and 3-undecanone. The long-lived free radicals observed in all of these compounds (RCHsCHCOR') are formed by the removal of one a proton from the parent ketone. The unpaired spin density in the 2p orbital adjacent to the carbonyl group is 0.81±0.08. A contour plot of the spin density as a function of the molecular orbital parameters is given. In qualitative agreement with the ESR results, the molecular orbital methods predict the position of maximum spin density to be adjacent to the carbonyl group.
Open Access
Electron spin resonance of X‑irradiated organic inclusion compounds
(Proceedings of the National Academy of Sciences, 1962-11) Griffith, O. H.; McConnell, H. M.
Open Access
Electron spin resonance study of X‑irradiated single crystals of di‑n‑ butyl oxalate‑urea and di‑n‑butyl malonate‑urea inclusion compounds
(Journal of Chemical Physics, 1970-12-01) Lai, A. A.; Birrell, G. B.; Griffith, O. H.
Open Access
ESR of an alkylalkoxyamino radical trapped in X‑irradiated decanal oxime O‑methyl ether‑urea inclusion crystals
(Journal of Chemical Physics, 1972-01-15) Ciecierska‑Tworek, Z; Birrell, G. B.; Griffith, O. H.
Open Access
Evidence for boundary lipid in membranes
(Proceedings of the National Academy of Sciences, 1973-02) Jost, P. C.; Griffith, O. H.; Capaldi, R. A.; Vanderkooi, G.
ABSTH\OT (Mochromc oxidase (EC 1.9.3.1) isolated from hccf-hcarl mitochondria with an appropriate phospholipid content forms vesicular structures. Lipid-protein interactions in this model membrane system were studied with the,lipid spin label, 16-doxylstearic acid. As the phospholipid/ prolein ratio is varied, two spectral components are ohserved. Al low phospholipid/prolcin ratios (<0.19 mg of phospholipid per mg of protein) the lipid spin label is liifCll!) immobilized. At higher phospholipid content an additional component characteristic of fluid lipid hilayers is evideiil. By summation of digilalized spectra and subsequent integration it was shown that all composite spec tra could he approximated by assuming only two com ponents arc present, and that the amount of phospholipid hound In Ihr protein is independent of the extent of the fluid hilaw-r region. The experimentally determined amount of phospholipid for maximum occupancy of pro- Iciii-hound niies is ahouI 0.2 mg of phospholipid per 1.0 nig itl protein. Iialiulalions show that this ralio is con sistent with a single layerof phospholipid surrounding the protein complex. The data are interpreted as evidence for a boundary of immobilized lipid between the hydrophobic protein and adjacent fluid hilayer regions in this membrane model system.
Open Access
A high vacuum photoelectron microscope for the study of biological specimens
(Scanning Electron Microscopy, 1981) Griffith, O. H.; Rempfer, G. F.; Lesch, G. H.
A photoelectron microscope (photoemission electron microscope) has been designed and built for the study of organic and biological samples. The microscope is an oil-free stainless steel high vacuum instrument pumped by a titanium sublimation pump, an ion pump, and molecular sieve roughing pumps. The electron lenses are of the electrostatic unipotential type. The microscope is equipped with a dewar for sample cooling, an internal cryogenic camera, TV-image intensifier, and vibration isolation support. Applications include studies of biological cell surfaces, photosynthetic membranes and aromatic chemical carcinogens. A representative micrograph of mouse 3T3 cells is included. In some respects, photoelectron micrographs resemble scanning electron micrographs, but the basis for contrast is different in these two techniques.
Open Access
Immunophotoelectron Microscopy: The Electron Optical Analog of Immunofluorescence Microscopy
(Proceedings of the National Academy of Sciences, 1985-01) Birrell, G. B.; Habliston, D. L.; Nadakavukaren, K. K.; Griffith, O. H.
The electron optical analog of immunofluo rescence microscopy combines three developments: (i) photoelectron microscopy to produce a high-resolution image of ex posed components of the cell, (jQ site-specific antibodies, and (iii) photoemissive markers coupled to the antibodies to make the distribution of sites visible. This approach, in theory, pro vides a way to extend the useful immunofluorescence micros copy technique to problems requiring much higher resolution. The resolution limit of fluorescence microscopy is limited to about 200 nm by the wavelength of the light used to form the image, whereas in photoelectron microscopy the image is formed by electrons (current resolution: 10-20 nm; theoretical limit: 5 nm or better depending on the electron optics). As a test system, cytoskeletons of CV-1 epithelial cells were pre pared under conditions that preserve microtubules, and the microtubule networks were visualized by both indirect immu nofluorescence and immunophotoelectron microscopy using colloidal gold coated with antibodies. Colloidal gold serves as a label for immunophotoelectron microscopy, providing en hanced photoemission from labeled cellular components so that they stand out against the darker background of the re maining unlabeled structures. In samples prepared for both immunofluorescence and immunophotoelectron microscopy, individual microtubules in the same cells were visualized by both techniques. The photoemissionof the colloidal gold mark ers is sufficiently high that the microtubules are easily recog nized without reference to the immunofluorescence micro graphs, indicating that this approach can be used, in combina tion with antibodies, to correlate structure and function in cell biological studies.
Open Access
Isotope effect on the paramagnetic resonance of triplet excitons
(Journal of Chemical Physics, 1965-10-15) Buckman, T. D.; Griffith, O. H.; McConnell, H. M.
Open Access
Lipid binding to the amphipathic membrane protein cytochrome b5
(Proceedings of the National Academy of Sciences, 1974-06) Dehlinger, P. J.; Jost, P. C.; Griffith, O. H.
ABSTRACT The lipid hinding properties of the membrane protein cytochrome b:. (detergent-extracted from calf liver microsomal preparations) were characterized by studying the interaction of spin-labeled lipid,- (5-, 12-, and 16-doxylstcaric acid and 5- and 16-cloxylphosphatidylcholine, where cloxyl refers to the nitroxide moiety) with cytochrome b :, using electron "pin resonance spectroscopy. The intact cytochrome b, n1olec11lc immobilizes all of the lipid spin label,;, while the segment of cytochrome b, released by trypsin doei. not afTcct lipid mobility. The immobilization of lipid spin label,-; on the h) ·drophohic surface of intact cytochrome b:, is not appreciably altered by associating the protein with liposomc" · DHTcrcnccs in polarity of the lipid binding site" between c, ·tochromc b, and phospholipid vc,.icles were also ob,-cr\'ed. The lipid binding sites on cytochrome b.; arc hydrophobic by conventional criteria, but arc more polar than the interior of fluid phospholipid bilayers.
Open Access
Lipid‑protein and lipid‑lipid interactions in cytochrome oxidase model membranes
(Journal of Supramolecular Structure, 1973) Jost, P. C.; Capaldi, R. A.; Vanderkooi, G.; Griffith, O. H.
Two lipid environments are dete cted in membranous cyto chrome oxidase , using spin labeling techniques. This model membrane system consists of closed vesicular membranes formed spontaneou sly when the mem hr,jlne protein is isolated with its accompanying phospholipids. The data show both an immobili zed componen t, which is constant in amount , and a fluid componen t. Based on spectral analysis, the interpretation is that the bound component repre sents a single layer of lipid immobilized on the surface of the protein between the hydrophobic protein complex and the adjacent fluid bilayer regions. Maximal enzyme activity of this functional protein complex is attained when all of the bound sites are occupied , and above this level additional phospholipid (bilayer) has little or no effect on the enzyme activity .
Open Access
Migration in polyacrylamide gels of the 80K protein substrate for protein kinase C in mouse fibroblasts is dependent on the choice of crosslinker
(Biotechniques, 1989) Hedberg, K. K.; Birrell, G. B.; Griffith, O. H.
Open Access
A nitroxide‑maleimide spin label
(Proceedings of the National Academy of Sciences, 1966-01) Griffith, O. H.; McConnell, H. M.
Open Access
Phorbol ester-induced actin cytoskeletal reorganization requires a heavy metal ion, probably Zn2+.
(Cell Regulation, 1991-12) Hedberg, K. K.; Birrell, G. B.; Griffith, O. H.
The cell-permeant heavy metal chelator N,N,N',Ntetrakis( 2-pyridylmethyl)ethylenediamine (TPEN) was found to counteract phorbol ester-induced actin reorganization in PTK2 and Swiss 3T3 cells. By us ing fluorescence and the higher resolution tech nique of photoelectron microscopy to monitor actin patterns, 15-min pretreatment with 25-50 pM TPEN was found to dramatically reduce actin alterations resulting from subsequent phorbol ester treatment in PTK2 cells. Similar results were obtained with Swiss 3T3 cells using 50 mM TPEN for 1.5 h. Phorbol ester-induced actin alterations are thought to de pend on activation of protein kinase C (PKC). In contrast to the phorbol ester effect, the PKC-independent actin cytoskeletal disruption caused by staurosporine and cytochalasin B was unaffected by TPEN pretreatment. TPEN did not block phorbol ester-induced activation of PKC in Swiss 3T3 cells, as observed by the phosphorylation of the 80K PKC substrate protein (MARCKS protein). TPEN also did not inhibit partially purified PKC from Swiss 3T3 cells in an in vitro PKC-specific commercial assay. To establish that the effect of TPEN is the removal of metal ions and not some other nonspecific effect of TPEN, a series of transition metal ions was added at the end of the TPEN pretreatment. The results indicate that the transient but dramatic phorbol ester-induced reorganization of the actin cytoskeleton in cultured cells depends on an inter action of PKC with a heavy metal, probably zinc.

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