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PubMed2005

Resistance of zwitterionic telomers accumulated on metal surfaces against nonspecific adsorption of proteins.

Telomers of N,N-dimethyl-N-(3-sulfopropyl)-3'-methacryloylaminopropanaminium inner salt (SPB), 2-methacryloyloxyethyl phosphorylcholine (MPC), and N,N-dimethyl-N-(1-carboxymethyl)-2'-methacryloyloxylethanaminium inner salt (CMB) were prepared by UV irradiation in the presence of N,N,N',N'-tetraethylthiuram disulfide and a disulfide-group-carrying iniferter (a compound which pursues initiation, chain transfer, and termination), Cys-BDC, which had been prepared by coupling N,N-diethyldithiocarbamoylmethylbenzoic acid succinimidyl ester with cystamine dihydrochloride. The telomers formed a self-assembled monolayer (SAM) on a gold electrode and a monolayer of colloidal gold deposited on a glass plate, as confirmed by the increase in potential difference (DeltaE(p)) of the voltammogram for hydroquinone as a probe using cyclic voltammetry (CV) and the increase in absorbance using localized surface plasmon resonance (LSPR) absorption spectroscopy, respectively. Nonspecific adsorption of various proteins onto the surfaces of various telomer SAMs was examined from the decrease in peak current (DeltaI) using CV and the absorption increase at 550 nm using LSPR absorption spectroscopy. The zwitterionic telomer SAM in general did not adsorb proteins significantly, suggesting the usability of zwitterionic polymer SAMs and brushes to coat various materials used in biomedical fields. The correlation between the structure of water in the vicinity of zwitterionic telomers and the resistance of the zwitterionic telomer SAMs against the nonspecific adsorption of proteins was discussed.

Absorption↗
PubMed2005

Antioxidant activity of gallic acid from rose flowers in senescence accelerated mice.

The activities of the antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx) in the blood and liver of the aging model induced by injection of different doses of D-gal into normal mice, and in senescence accelerated mice (SAM) of different ages, were determined. The results showed that the enzyme activities in the D-gal treated mice did not alter appreciably but the enzyme activities in blood of the SAM declined significantly with the increase in age, especially in the 9-month-old SAM. When gallic acid purified from rose flowers was used to treat the 9-month-old male SAM, it not only reinstated the activities of CAT and GPx but also significantly reduced the amount of malondialdehyde (MDA) in the liver, brain and kidney. The results demonstrated that 9-month-old male SAM represent an appropriate animal model to evaluate the antioxidant activities of natural products.

Aging↗
PubMed2005

Surface-associated material from Porphyromonas gingivalis stimulates the release of nitric oxide by inducing expression of inducible nitric oxide synthase.

The purpose of this study was to examine the effects of surface-associated material (SAM) from Porphyromonas gingivalis, a major cause of inflammatory periodontal disease, on the production of nitric oxide (NO) and expression of inducible nitric oxide synthase (iNOS) in the murine macrophage cell line RAW264.7. We also attempted to throw light on the signaling mechanisms involved in P. gingivalis SAM-induced NO production. SAM from P. gingivalis 381 was obtained by saline extraction. NO production was assayed by measuring the accumulation of nitrite in culture supernatants. Western blot analysis of iNOS and analysis of reverse transcription-polymerase chain reaction (RT-PCR) products were carried out. We found that P. gingivalis SAM can induce iNOS expression and stimulate the release of NO without additional stimuli and demonstrated an important role of the transcription factor NF-kappaB and microtubule polymerization in NO production. The production of NO required L-arginine, protein tyrosine kinase, and protein kinase C. The ability of P. gingivalis SAM to promote the production of NO may be important in the pathogenesis of inflammatory periodontal disease.

Animals↗
PubMed2005

The transmethylation cycle in the brain of Alzheimer patients.

Homocysteine accumulation, frequently observed in plasma of AD patients, may be a sign of a reduced activity of the brain methionine-homocysteine transmethylation cycle. S-Adenosylmethionine (SAM) is the main methyl donor in several transmethylation reactions. The demethylated product of SAM, S-adenosylhomocysteine (SAH), is hydrolyzed to yield homocysteine, which can be remethylated to methionine by transfer of a methyl group of 5-methyltetrahydrofolate (5-MTHF). A reduced activity of the transmethylation cycle in the brain may result in hypomethylation of the promoter of the presenilin 1 (PS1) gene, which will lead to overexpression of presenilin 1 and, consequently, to increased Abeta(1-42) (Abeta42) formation. Brain transmethylation was studied in 30 patients with 'probable' AD and 28 age-matched non-demented controls by measuring the cerebrospinal fluid (CSF) levels of SAM, SAH and 5-MTHF. 5-MTHF was determined by HPLC with electrochemical detection, while SAM and SAH were assayed by stable isotope dilution tandem mass spectrometry. We found no statistical differences between AD patients and controls for 5-MTHF, SAM and SAH levels, and the SAM/SAH-ratio in CSF. These findings argue against a possible change in methylation of the promoter and expression of PS1.

Aged↗
PubMed2004

Determination of language dominance with synthetic aperture magnetometry: comparison with the Wada test.

Cerebral dominance for language function was investigated with synthetic aperture magnetometry (SAM). The results were compared with those of the Wada test. SAM is a spatial filtering technique that enables demonstration of the spatiotemporal distribution of oscillatory changes (synchronization and desynchronization) in magnetoencephalography (MEG) signals elicited by specific brain activation. MEG was conducted during a silent reading task in 20 consecutive preoperative neurosurgical patients who also underwent a Wada test. The spatial distribution of oscillatory changes related to silent reading was shown tomographically with SAM as statistical images. Language dominance was estimated by the laterality index, which scales the lateralization of the beta (13-25 Hz) and low gamma (25-50 Hz) band desynchronizations in the inferior frontal gyrus (IFG) or middle frontal gyrus (MFG). Oscillatory changes were distributed multifocally and bilaterally in the occipital cortex, IFG or MFG, and temporo-parieto-occipital border regions. In 19 patients (95%), language lateralization estimated by the laterality index was congruent with the result of the Wada test. In left-handed patients, SAM analysis clearly differentiated language dominance (left, right, or bilateral), and the findings were confirmed by the Wada test. Lateralization of beta or low gamma band desynchronizations in the IFG or MFG is a good indicator of the side of language dominance. Reliability of MEG imaging with SAM is sufficient to evaluate language dominance preoperatively in neurosurgical patients.

Adolescent↗
PubMed2004

S-adenosylmethionine: nothing goes to waste.

S-adenosylmethionine (SAM or AdoMet) is a biological sulfonium compound known as the major biological methyl donor in reactions catalyzed by methyltransferases. SAM is also used as a source of methylene groups (in the synthesis of cyclopropyl fatty acids), amino groups (in the synthesis of 7,8-diaminoperlagonic acid, a precursor of biotin), ribosyl groups (in the synthesis of epoxyqueuosine, a modified nucleoside in tRNAs) and aminopropyl groups (in the synthesis of ethylene and polyamines). Even though the mechanism of most of these reactions has not been extensively characterized, it is likely that the chemistry at work is mainly driven by the electrophilic character of the carbon centers that are adjacent to the positively charged sulfur atom of SAM. In addition, SAM, upon one-electron reduction, is a source of 5'-deoxyadenosyl radicals, which initiate many metabolic reactions and biosynthetic pathways by hydrogen-atom abstraction. SAM presents a unique situation in which all constituent parts have a chemical use.

4-Butyrolactone↗
PubMed2004

Observation of removal of an Fmoc protecting group by scanning tunneling microscopy.

We demonstrate here by imaging successive surface reactions in self-assembled monolayers (SAMs) on Au(111) at molecular scale with a scanning tunneling microscope (STM): (i) SAM matrices formation with 1-octanethiol on Au(111) in ethanol, (ii) insertion of N-Fmoc-aminooctanethiol into the SAM matrices in ethanol, and (iii) removal of the Fmoc protecting group with tris(2-aminoethyl)amine (TAEA). The total reaction is formation of SAMs containing a small amount of NH2 terminated molecules in the CH3 terminated SAM matrices. After the reaction of the protecting group with TAEA, STM imaging revealed the decrease in heights of the inserted molecules on average. We attributed this observation to removal of the protecting group by taking account of a convolution of electronic and topographic contributions to observed STM heights. Apparent areas of the terminal groups, however, became larger on removal. The increase in the areas was attributed to water adsorption to the NH2 terminal group under air.

Journal Article↗
PubMed2002

Self-assembled monolayers of globotriaosylceramide (Gb3) mimics: surface-specific affinity with shiga toxins.

Self-assembled monolayers (SAMs) of Gb3 mimics having different lengths of alkyl chains were prepared on gold surfaces, and their interactions with galactose-specific lectin (RCA(120)) and Shiga toxins (Stxs) were investigated by a quartz crystal microbalance (QCM) in aqueous solutions. Their interaction with RCA(120) was enhanced owing to the "cluster effect," regardless of the alkyl chain length of the SAMs. The interaction with Stxs was dependent on the alkyl chain length of Gb3 mimics. Stx-1 and Stx-2 showed a stronger affinity to the Gb3C2 SAM with ethyl disulfide and to the Gb3C10 with decyl disulfide, respectively. Gb3 glycoconjugate polymer with no alkyl spacer inhibited the adsorption of Stx-1 to Gb3C10 SAM but did not inhibit the adsorption of Stx-2 to Gb3C10 SAM. The results suggest that the alkyl chain of the glycolipid takes part in the binding to Stx-2 but not to Stx-1, which is also supported by the computer simulation of Stx-1 with a Gb3 model substance.

Adsorption↗
PubMed1995

Phosphatidylethanolamine N-methyltransferase activity in isolated rod outer segments from bovine retina.

Phosphatidylcholine (PC) can be synthesized in isolated rod outer segments from bovine retina by successive transfer of methyl groups from S-adenosyl-L-methionine (SAM) to phosphatidylethanolamine (PE), with the intermediate formation of phosphatidyl-N-monomethylethanolamine (PMME) and phosphatidyl-N,N-dimethylethanolamine (PDME). This reaction is time-protein-and SAM concentration-dependent. Phosphatidylethanolamine N-methyltransferase (PE N-MTase) has two pH optima, 8.5 and 10, at low (10 microM) and high (200 microM) SAM concentrations and requires magnesium ions for full activity. When ROS membranes were incubated at 5 to 200 microM SAM concentrations at pH 8.5 or pH 10, the major methylated product was PMME, followed by PC and PDME. The apparent Kms for SAM at pH 8.5 and at pH 10 were similar (37 and 38 microM, respectively). The Vmax was 13 pmol h-1 (mg protein)-1 at pH 8.5 and 12.50 pmol h-1 (mg protein)-1 at pH 10. Pulse-chase experiments demonstrated a precursor-product relationship with [3H]PC as the end product. The level of PE N-Mtase activity in the purified ROS preparation obtained from crude ROS fractions by discontinuous sucrose gradient centrifugation, was as high as 65% of the level found in the microsomal fraction obtained from the remainder of the retinas. The presence of microsomal and mitochondrial marker enzymes, however, was minimal in the ROS preparation. The radioactivity incorporated into ROS PC was measured in an upper and lower band of PC obtained by two-dimensional TLC. We found that the amount of [methyl-3H] groups incorporated into the upper PC band was 2.5-fold greater than that incorporated into the lower one. The fatty acid composition of the upper band was very different from that of the lower band, the former being enriched in very long-chain polyunsaturated fatty acids and the latter in saturated fatty acids. Phosphatidyl-ethanolamine N-methyltransferase activity increased in the presence of exogenous phospholipid substrates. PDME being augmented ten-fold and PC eight-fold when the incubations were carried out in the presence of PMME and PDME, respectively. At a 2 mM concentration, S-adenosyl-L-homocysteine (SAH) inhibited the methyl groups' incorporation into the endogenous phospholipids by 40%. When ROS membranes were selectively depleted of soluble or peripheral and soluble proteins, the PE N-MTase activity remained mainly associated to the membrane, suggesting that this enzyme (s) is an intrinsic membrane protein.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2001

Increasing levels of dietary homocystine with carotid endarterectomy produced proportionate increases in plasma homocysteine and intimal hyperplasia.

PURPOSE: The role that homocysteine may play in post-carotid endarterectomy (CEA) restenosis due to intimal hyperplasia is not well understood. This study was designed to investigate the effects of different levels of dietary homocystine on: (1) plasma homocysteine; (2) post-CEA intimal hyperplasia; and (3) levels of the methyl donor S-adenosylmethionine (SAM) and its counterpart S-adenosylhomocysteine (SAH) in the homocysteine pathway. METHODS: Male rats were fed specialized diets for 2 weeks pre- and post-CEA. Groups included control (0 homocystine added, n=9), 1.5 (1.5 g/kg homocystine added, n=10), 3.0 (3.0 g/kg homocystine added, n=9), and 4.5 (4.5 g/kg homocystine added, n=11). The rats underwent a surgical carotid endarterectomy. Endpoints included; plasma homocysteine, intimal hyperplasia, replicative index using with alpha-SM actin and BrdU, hepatic SAM levels, SAH levels, and the hepatic activities of methylenetetrahydrofolate reductase (MTHFR) and cystathionine beta-synthase (CBS). RESULTS: Increasing dietary homocystine produced a proportionate increase in plasma homocysteine and an increase in intimal hyperplasia. Regression analysis of plasma homocysteine levels and intimal hyperplasia showed a significant correlation (r=0.71,P=0.003). Plasma homocysteine levels above 15 microM were associated with significant increases in intimal hyperplasia above 6.5% (P=0.04). Elevation of plasma homocysteine levels to moderate levels (5-25 microM) resulted in significant post-CEA intimal hyperplasia. Cellular analysis of the area of intimal hyperplasia in all diet groups showed comparable amounts of cells positive for alpha-SM actin. However, with increasing levels of dietary homocystine and plasma homocysteine there was an increase in replicative index (P<0.001) as determined by BrdU staining. Increasing dietary homocystine increased plasma homocysteine and was followed by increases in the replicative index thus producing increased intimal hyperplasia and lumenal stenosis. In hepatic measurements the 1.5 and 3.0 g/kg homocystine diets caused: increased liver activity of MTHFR (P=0.03) and decreased hepatic levels of SAM, SAH and SAM/SAH ratios compared to controls. Homocystine treatment did not cause significant alterations in CBS levels (P=0.992). These studies also showed no correlation of the MTHFR and CBS enzymes with plasma homocysteine levels or intimal hyperplasia. However, hepatic levels of SAM showed significant negative correlations with plasma homocysteine (r=-0.58; P=0.006) and with BrdU percentages of cellular proliferation (r=-0.69; P=0.06). CONCLUSION: The degree of post-CEA intimal hyperplasia in a rat model is directly related to the plasma level of homocysteine. The hyperplastic effects of homocysteine may be mediated in part by a physiological insufficiency of methyl donors as shown by decreases in SAM. Thus, increasing levels of plasma homocysteine enhanced and accelerated the smooth muscle cell response after CEA which led to increased intimal hyperplasia and lumenal stenosis.

Animals↗
PubMed1978

Affinity chromatography of an S-adenosylmethionine-dependent methyltransferase using immobilized S-adenosylhomocysteine. Purification of the indolethylamine N-methyltransferases of phalaris tuberosa.

In the cases that have been studied so far, S-adenosylhomocysteine (SAH) is a powerful inhibitor of S-adenosylmethionine (SAM) binding to SAM-dependent methyltransferases. We deduced, from the available data on the binding of SAM and SAH analogues to SAM dependent methyltransferases, that linkage of SAH through the carboxyl group to an immobilized support would lead to a more general affinity adsorbent for SAM-dependent methyltransferases than linkage through other functional groups. This paper describes the synthesis of this affinity adsorbent and its use to purify the two indolethylamine N-methyltransferases of Phalaris tuberosa.

Australia↗
PubMed1997

Depletion of nigrostriatal and forebrain tyrosine hydroxylase by S-adenosylmethionine: a model that may explain the occurrence of depression in Parkinson's disease.

The loss of nigrostriatal tyrosine hydroxylase (TH), dopamine and dopaminergic neurons are the major pathology of Parkinson's disease (PD). These catecholaminergic changes are responsible for the symptoms of tremor, hypokinesia and rigidity. Depression is also a major symptom in PD, but the cause is unknown. The impairments of catecholaminergic fibers in the frontal lobe may be involved, because the frontal lobe of the cerebrum is involved in the regulation of mood, and decreased catecholaminergic activity in the frontal lobe is related to behavioral depression. The changes that damage the nigrostriatal dopamine system and induce motor impairments may also damage the forebrain catecholamine fibers and induce depression. It means that manipulations that damage the nigrostriatum (NS) and induce parkinsonism may also deplete TH in the frontal cortex. Such an effect would suggests a basis for the depression seen in PD. The injection of S-adenosyl-L-methionine (SAM), the biological methyl donor, into the brain of rats damaged the NS, depleted TH and caused tremor and hypokinesia. SAM may interfere also with the forebrain TH, which may help to explain the occurrence of depression in PD. Experiments were designed to test such a hypothesis. The results showed that SAM caused a loss of immunoreactive nerve fibers and it decreased the intensity of TH-immunoreactivity (IR) in the frontal cortex. These changes were accompanied with the loss of cells and the depletion of TH-IR from nerve fibers in the SN and the caudate nucleus. Other studies showed that SAM depletes DA and since SAM induces PD-like changes the results may be relevant to the co-occurrence of PD symptoms and depression. A single biological manipulation may impair the nigrostriatal dopaminergic neurons as well as the frontal cortex catecholaminergic fibers.

Animals↗
PubMed1999

Methionine reduces spontaneous and alkylation-induced mutagenesis in Saccharomyces cerevisiae cells deficient in O6-methylguanine-DNA methyltransferase.

The exposure of DNA to reactive intracellular metabolites is thought to be a major cause of spontaneous mutagenesis. DNA alkylation is implicated in the above process by the fact that bacterial and yeast cells lacking DNA alkylation-specific repair genes exhibit elevated spontaneous mutation rates. The origin of the intracellular alkylating molecules is not clear; however, S-adenosylmethionine (SAM) has been proposed as one source because it has a reactive methyl group known to methylate proteins and DNA. We supplemented yeast cultures with excess methionine and examined the effects of increased endogenous SAM concentration on spontaneous and alkylation-induced mutagenesis in the absence of various DNA repair pathways. Our results show that either the excess methionine, or the increased SAM produced as a result of this treatment, is able to protect yeast cells from mutagenesis, and that this effect is alkylation-damage-specific. The protective effect was observed only in the mgt1 mutant deficient in the O(6)-methylguanine-DNA repair methyltransferase, but not in the wild type or other DNA repair-deficient strains, indicating that the protection is specific for O-methyl lesions. Thus, our results may lend support to the recently reported chemopreventive effect of SAM in rodents and further suggest that the observed tumor prevention by SAM may be, in part, due to its suppression of spontaneous mutagenesis in mammals. Given that a strong correlation has been established between O(6)-methylguanine and carcinogenicity, this study may offer a novel approach to preventing carcinogenesis.

Alkylation↗
PubMed2006

Management of severe acute malnutrition in children.

Severe acute malnutrition (SAM) is defined as a weight-for-height measurement of 70% or less below the median, or three SD or more below the mean National Centre for Health Statistics reference values, the presence of bilateral pitting oedema of nutritional origin, or a mid-upper-arm circumference of less than 110 mm in children age 1-5 years. 13 million children under age 5 years have SAM, and the disorder is associated with 1 million to 2 million preventable child deaths each year. Despite this global importance, child-survival programmes have ignored SAM, and WHO does not recognise the term "acute malnutrition". Inpatient treatment is resource intensive and requires many skilled and motivated staff. Where SAM is common, the number of cases exceeds available inpatient capacity, which limits the effect of treatment; case-fatality rates are 20-30% and coverage is commonly under 10%. Programmes of community-based therapeutic care substantially reduce case-fatality rates and increase coverage rates. These programmes use new, ready-to-use, therapeutic foods and are designed to increase access to services, reduce opportunity costs, encourage early presentation and compliance, and thereby increase coverage and recovery rates. In community-based therapeutic care, all patients with SAM without complications are treated as outpatients. This approach promises to be a successful and cost-effective treatment strategy.

Child, Preschool↗
PubMed2003

Localization of human somatosensory cortex using spatially filtered magnetoencephalography.

A spatial filter algorithm based on minimum-variance beamforming (synthetic aperture magnetometry (SAM)) was applied to single trial neuromagnetic recordings in order to localize primary somatosensory cortex. Magnetoencephalography (MEG) responses to electrical stimulation of the right and left median nerve were recorded using a whole-head MEG system and localized using both SAM spatial filtering and dipole analysis. Spatial filtering was applied to single trial neuromagnetic recordings to produce 3-dimensional difference images of source power between active (0-50 ms) and control states (-50-0 ms) in the range of 15-300 Hz. Average difference between N20m dipole location and location of maximal increase in power in the SAM images was 3.7 mm (1.5 mm SD) and localized to primary somatosensory cortex. Time-frequency analysis of spatially filtered output for the peak SAM locations showed a brief (10 ms) increase in the 60-100 Hz band coincident with the N20m response and a longer duration (approx. 80 ms) increase in power in the 10-40 Hz band following N20m onset. These results indicate that beamformer based spatial filter methods such as SAM can be used to localize temporally discrete cortical activity produced by median nerve stimulation.

Adult↗
PubMed2002

Stabilization of S-adenosyl-L-methionine promoted by trehalose.

S-adenosyl-L-methionine (SAM), an important metabolic intermediate of mammals, is a well-known therapeutic agent. The molecule is chemically unstable, both in solution and in dry state, and forms different degradation products. Because the chemical instability represents a real problem during the preparation of therapeutic formulations, we investigated the capacity of some sugars to improve the SAM stability over time. In the present work, we demonstrated that the disaccharide trehalose exercises a protective effect towards the lyophilized SAM slackening its degradation (65% of SAM was detected after 50 days at 37 degrees C). A parallel study, performed to stabilize the SAM into lyophilized yeast cells enriched in the sulfonium compound, assessed the positive effect of trehalose also in whole cells, but in lesser measure.

Drug Stability↗
PubMed2002

Role of abnormal methionine metabolism in alcoholic liver injury.

Methionine catabolism occurs mostly in the liver through the formation of S-adenosylmethionine (SAM) in a reaction catalyzed by methionine adenosyltransferase (MAT). S-adenosylmethionine is the principal biologic methyl donor, a precursor for polyamines, and in liver, it is also a precursor for reduced glutathione (GSH). Liver-specific and non-liver-specific MAT are products of two different genes, MAT1A and MAT2A, respectively. Mature liver expresses MAT1A, whereas MAT2A is expressed in extrahepatic tissues and induced during liver growth and de-differentiation. The type of MAT expressed by the cell affects the steady-state SAM level, DNA methylation, and growth rate. This has been demonstrated further by using the MAT1A knockout mouse model in which hepatic SAM and GSH levels decrease, the liver becomes larger and more susceptible to injury, and steatohepatitis develops spontaneously. Altered methionine metabolism in alcoholic liver disease results in decreased transmethylation and transsulfuration, changes that may play important pathogenic roles. Major changes include a relative switch in MAT expression; decreased hepatic SAM, GSH, and DNA methylation levels; decreased homocysteine metabolism; and hyperhomocysteinemia. Consequences of hepatic DNA hypomethylation include increased expression of c-myc and DNA strand break accumulation. One possible consequence of hyperhomocysteinemia is increased fibrogenesis. Abnormal methionine metabolism may also occur in Kupffer cells, which express both forms of MAT. If SAM levels also decrease in these cells, this may contribute to the induction of tumor necrosis factor (TNF) expression and release. In summary, altered hepatic methionine metabolism can have serious consequences that affect not only hepatocytes, but also hepatic stellate and Kupffer cells. These changes can lead to impaired antioxidant defense, altered gene expression, promotion of fibrogenesis, and even hepatocarcinogenesis.

Animals↗
PubMed2000

Study of complement activation on well-defined surfaces using surface plasmon resonance.

It has been accepted that covalent immobilization of C3b on artificial materials is the most important step to initiate the complement activation. However, there are few studies that have directly demonstrated covalent immobilization of C3b on artificial surfaces. In this study, model thin layers were prepared by the self-assembled monolayer method to produce a surface covered with hydroxyl or methyl groups using mercaptododecane (CH(3)-SAM) and mercaptoundecanol (OH-SAM). Interactions of the complement system with the model surfaces were studied using a surface plasmon resonance instrument. The OH-SAM immobilized C3b, resulting in activating of the complement system through the alternative pathway in Veronal-buffered saline, but this surface did not activate the classical pathway. However, the OH-SAM could not activate the alternative pathway in Veronal-buffered saline containing 10 mM EGTA and 2 mM MgCl(2) that is believed not to interfere with the activation of the alternative pathway. The hydrophobic CH(3)-SAM surface could not activate the classical pathway, but activated the alternative pathway, although the extent was small.

Journal Article↗