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E Haag

Publications and source records attributed to E Haag.

9 recordsLinked to original sources
PubMed1998

Cutaneous lung tissue heterotopia.

AIMS: We describe the clinical and pathological findings of a previously unreported cutaneous lung tissue heterotopia in a child. CASE DETAILS: The 3-year-old female patient developed a 8-mm secreting papule over her left scapula. Pathological examination revealed a lesion composed of bronchioles and alveoli within the subcutis and the dermis, with bronchiolar connection to the epidermis. Alveolar type II cells indicating full pulmonary differentiation were detected with a monoclonal antibody (AMH 152). CONCLUSIONS: The described features suggest that this lesion is a unique variant of rarely observed bronchus-like entities of the skin, designated as cutaneous bronchogenic cysts or cutaneous branchial cleft cysts.

Bronchogenic Cyst↗
PubMed1995

Involvement of the CP47 protein in stabilization and photoactivation of a functional water-oxidizing complex in the cyanobacterium Synechocystis sp. PCC 6803.

Oscillation patterns of the oxygen yield per flash induced by a train of single-turnover flashes were measured as a function of dark incubation and different pre-illumination conditions in several autotrophic mutant strains of Synechocystis sp. PCC 6803 carrying short deletions within the large, lumen-exposed hydrophilic region (loop E) of the chlorophyll a-binding photosystem II protein CP47. A physiological and biochemical characterization of these mutant strains has been presented previously [Eaton-Rye, J. J., & Vermaas, W. F. J. (1991) Plant Mol. Biol. 17, 1165-1177; Haag, E., Eaton-Rye, J. J., Renger, G., & Vermaas, W. F. J. (1993) Biochemistry 32, 4444-4454], and some functional properties were described recently [Gleiter, H. M., Haag, E., Shen, J.-R., Eaton-Rye, J. J., Inoue, Y., Vermaas, W. F. J., & Renger, G. (1994) Biochemistry 33, 12063-12071]. The present study shows that in several mutants the water-oxidizing complex (WOC) became inactivated during prolonged dark incubation, whereas the WOC of the wild-type strain remained active. The rate and extent of the inactivation in the mutants depend on the domain of loop E, where 3-8 amino acid residues were deleted. The most pronounced effects are observed in mutants delta(A373-D380) and delta(R384-V392). A competent WOC can be restored from the fully inactivated state by illumination with short saturating flashes. The number of flashes required for this process strongly depends on the site at which a deletion has been introduced into loop E. Again, the most prominent effects were found in mutants delta(A373-D380) and delta(R384-V392). Interestingly, the number of flashes required for activation was reduced by more than an order of magnitude in both mutants by the addition of 10 mM CaCl2 to the cell suspension. On the basis of a model for photoactivation proposed by Tamura and Cheniae (1987) [Biochim. Biophys. Acta 890, 179-194], a scheme is presented for the processes of dark inactivation and photoactivation in these mutants. The results presented here corroborate an important role of the large hydrophilic domain (loop E) of CP47 in a functional and stable WOC.

Amino Acid Sequence↗
PubMed1994

Functional characterization of mutant strains of the cyanobacterium Synechocystis sp. PCC 6803 lacking short domains within the large, lumen-exposed loop of the chlorophyll protein CP47 in photosystem II.

Several autotrophic mutant strains of Synechocystis sp. PCC 6803 carrying short deletions or a single-site mutation within the large, lumen-exposed loop (loop E) of the chlorophyll a-binding photosystem II core protein, CP47, are analyzed for their functional properties by measuring the flash-induced pattern of thermoluminescence, oxygen yield, and fluorescence quantum yield. A physiological and biochemical characterization of these mutant strains has been given in two previous reports [Eaton-Rye, J.J., & Vermaas, W.F.J. (1991) Plant Mol. Biol. 17, 1165-1177; Haag, E., Eaton-Rye, J.J., Renger, G., & Vermaas, S. F.J. (1993) Biochemistry 32, 4444-4454]. The results of the present study show that deletion of charged and conserved amino acids in a region roughly located between residues 370 and 390 decreases the binding affinity of the extrinsic PS II-O protein to photosystem II. Marked differences with PSII-O deletion mutants are observed with respect to Ca2+ requirement and the flash-induced pattern of oxygen evolution. Under conditions where a sufficient light activation is provided, the psbB mutants assayed in this study reveal normal S-state parameters and lifetimes. The results bear two basic implications: (i) the manganese involved in water oxidation can still be bound in a functionally normal or only slightly distorted manner, and (ii) the binding of the extrinsic PS II-O protein to photosystem II is impaired in mutants carrying a deletion in the domain between residues 370 and 390, but the presence of the PS II-O protein is still of functional relevance for the PS II complex, e.g., for maintenance of a high-affinity binding site for Ca2+ and/or involvement during the process of photoactivation.

Binding Sites↗
PubMed1994

[Cholesterol crystal embolisms due to systemic thrombolysis of an acute myocardial infarct].

A 63-year-old male patient admitted with acute inferior myocardial infarction was treated with tissue plasminogen activator (rt-PA) and heparin. 4 hours after the initiation of the rt-PA infusion he showed painful cutaneous alterations on the lower trunk, mistaken as drug-induced rash and later correctly identified as livedo reticularis. Simultaneously, renal function deteriorated. Assuming hypersensitivity vasculitis, we instituted immunosuppressive treatment which proved to be ineffective. Skin biopsy including the deeper layers showed multiple cholesterol emboli. Anticoagulants were stopped and we noticed no further cholesterol embolism or further decline of renal function. 10 previous publications have mentioned a causal relationship between systemic fibrinolytic treatment and the cholesterol crystal embolism syndrome. In 7 cases, however, angiographic procedures were used or the interval between fibrinolysis and the occurrence of cholesterol crystal embolism was too long to exclude spontaneous or heparin-induced cholesterol crystal embolism. The short interval in our own case points clearly to the systemic fibrinolytic therapy as the culprit. We would like to draw attention to the possibility that in individuals with advanced atherosclerotic lesions of the aorta or major arteries, systemic fibrinolytic treatment of myocardial infarction may give rise to the cholesterol crystal embolism syndrome.

Embolism, Cholesterol↗
PubMed1993

Functionally important domains of the large hydrophilic loop of CP47 as probed by oligonucleotide-directed mutagenesis in Synechocystis sp. PCC 6803.

The chlorophyll a-binding protein CP47 serves as core antenna to photosystem II (PS II). The predicted topology of CP47 exhibits six membrane-spanning regions and a large hydrophilic loop (loop E) which roughly includes 200 residues (255-455) and is presumably exposed to the lumenal side of the thylakoid membrane. Several lines of experimental evidence suggest that loop E might be involved in binding or stabilizing functional manganese in the catalytic site of water oxidation or in interacting with the extrinsic PS II-O protein (the 33-kDa manganese-stabilizing protein). To scan loop E for functionally important domains, oligonucleotide-directed mutagenesis has been used to introduce deletions of 3-8 residues in conserved and charged regions of loop E. In addition, one single-site mutation of the only histidine present in loop E was created (H343L). Domains deleted in delta 1 (I265-F268), delta 2 (T271-K277), delta 4 (T304-L309), delta 5 (F311-N317), and delta 12 (D440-P447) are required for stable assembly of functional PS II complexes. Deletion of domains delta 3 (K277-E283) and delta 11 (R422-E428) significantly reduces the level of assembled PS II and impairs photoautotrophic growth and oxygen evolution. Deletion of domain delta 8 (A373-D380) enhances the susceptibility to photoinhibition. In contrast, deletion of domains delta 6 (G333-I336), delta 7 (K347-R352), delta 9 (V392-Q394), and delta 10 (D416-F420) and mutation of H343 to leucine do not seem to severly interrupt PS II structure and function, although all mutants exhibit a slightly decreased stability of PS II as compared to the wild type. Thus, selected domains of the large hydrophilic loop of CP47 are important for PS II structure and function. With respect to possible sites of interaction between loop E of CP47 and the extrinsic PS II-O protein, our results indicate that none of the deletions in the region from residue 330 to 420 (delta 6, delta 7, delta 8, delta 9, delta 10) completely interrupts a functional association of the manganese-stabilizing protein to PS II, although the binding characteristics might be changed in some cases.

Amino Acid Sequence↗
PubMed1992

Photoinhibition affects the non-heme iron center in photosystem II.

Effects on the PS II acceptor side caused by exposure to strong white light (180 W/m2) of PS II membrane fragments (spinach) at pH 6.5 and 0 degrees C were analyzed by measuring low temperature EPR signals and flash-induced transient changes of the fluorescence quantum yield. The following results were obtained: (a) the extent of the light induced g = 1.9 EPR signal as a measure of photochemical Fe2+QA- formation declines with progressing photoinhibition. The half-life of this effect is independent of the absence or presence of an exogenous electron acceptor during the photoinhibitory treatment; (b) in samples photoinhibited in the absence of an electron acceptor and subsequently incubated with K3[Fe(CN)6] in the dark, the extent of the g = 8 EPR signal (reflecting the oxidized Fe3+ form of the endogenous non-heme iron center) and of the flash-induced change of the fluorescence yield (as a measure of fast electron transfer from QA- to Fe3+ after the first flash; [see (1992) Photosynth. Res. 31, 113-126] exhibits the same dependence on photoinhibition time as the g = 1.9 EPR signal; (c) in samples photoinhibited in the presence of an exogenous electron acceptor, the signals reflecting Fe(3+)-formation and fast electron transfer from QA- to Fe3+ decline faster than the g = 1.9 EPR signal. These results provide for the first time direct evidence that the endogenous non-heme iron center located between QA and QB is susceptible to modifications by light stress. The implications of this finding will be discussed.

Cations↗
PubMed1990

Functional and structural analysis of photosystem II core complexes from spinach with high oxygen evolution capacity.

Oxygen-evolving photosystem II core complexes were prepared from spinach by solubilizing photosystem II membrane fragments with dodecyl-beta-D-maltoside. The core complexes consist of the intrinsic 47-kDa, 43-kDa, D1 and D2 polypeptides, the two subunits of cytochrome b559 and the extrinsic 33-kDa protein. In the presence of 50 mM CaCl2 they exhibit a high oxygen evolution rate of 1.3 +/- 0.2 mmol O2.mg chlorophyll-1.h-1 with either 2,6-dichloro-benzoquinone or K3[Fe(CN)6] as acceptor. Electron micrographs of these complexes reveal an obtuse triangular structure in when viewed from the top measuring 15.3 nm on one side and 10.6 nm on the other two sides. An average height of 7.3 nm was determined from the side view position. These data are in good agreement with previously reported dimensions for photosystem II core complexes [Irrgang, K.-D., Boekema, E. J., Vater, J. and Renger, G. (1988) Eur. J. Biochem. 178, 209-217]. In contrast to previous reports the extrinsic 33-kDa subunit could be resolved for the first time. It appears as a small protrusion when the complex is viewed from the side and seems to cover the lumenal side of the core complex appearing as a disk with a thickness of 1.5-3.3 nm.

Centrifugation, Density Gradient↗