Molecular biomarkers molecules

Acid- and alkaline phosphatases act on a variety of mono- and multiple phosphate carrying low molecular mass molecules. In addition, they hydrolyze many, but not all, phosphoproteins. They are in use for decades to easily screen for diseases, however, somewhat unspe-cifially. For instance, acid phosphatase is used as biomarker for prostate cancer, and alkaline phosphatase to monitor bone (de-) mineralization and liver tumors. 

Due to the complexity of organic matter sources in estuaries and the aforementioned problems associated with making only bulk measurements to constrain them, the application of chemical biomarkers has become widespread in estuarine research (see review, Bianchi and Canuel, 2001). The term biomarker molecule has recently been defined by Meyers (2003, p. 262) as compounds that characterize certain biotic sources and that retain their source information after burial in sediments, even after some alteration. This molecular information is more specific and sensitive than bulk elemental and isotopic techniques in characterizing sources of organic matter, and further allows for identification of multiple sources (Meyers, 1997, 2003). 

Another example is the accurate determination of small biomarker molecules in blood. Detection of low-abundance-low-molecular-weight (MW) biomarkers (small molecules or peptides) in blood, using mass spectrometry, can often be challenging. These low-MW molecules tend to undergo noncovalent... 

Anaerobic CH4 oxidation, now referred to as anaerobic oxidation of methane (AOM), has received renewed attention with introduction of new organic geochemical and molecular techniques. Hinrichs et al. (1999) applied compound-specific isotope analyses of lipid biomarker molecules associated with specific archea and culture-independent techniques involving 16S rRNA identification studies to samples collected from an Eel River Basin seep. This work showed that the biomarker compounds were so strongly depleted in that CH4 must be the source rather... 

Rather interestingly, the oldest usable biomarkers in carbonaceous shales date from the Neoarchean. Molecular fossils extracted from 2.5 Ga to 2.7 Ga shales of the Fortescue and Hamersley groups in the Pilbara Craton, Western Australia, indicate that the photic zone of the water column in the areas where these shales were deposited was probably weakly oxygenated, and that cyanobacteria were part of the microbial biota (Brocks et al., 1999, 2002 Summons et al., 1999). The similarity of the timing of the rise in the range of in sediments and the earliest evidence for the presence of cyanobacteria may, however, be coincidental, because to date no sediments older than 2.7 Ga have been found that contain usable biomarker molecules (Brocks, personal communication, 2002). 

There are two main types of geochemical proxy used to identify former life. These are biomarker molecules and isotopic fractionations. Biomarker molecules are specific molecules preserved in sediments as molecular fossils, which are unambiguous indicators of their biological precursors. Some of the most successful... 

A different study purely focused on isolating carrier molecules and their bound proteins to search for biomarkers of clinical interest. It was not only found that circulating carrier proteins were reservoirs for the accumulation and amplification of putative disease markers but also that the low molecular mass proteins that bound to albumin were distinct from those bound to nonalbumin carriers. Using SELDI-TOF, it was further verified that albumin bound peptides associated with ovarian cancer. This demonstrated that albumin capture was an effective method for harvesting disease-relevant biomarkers [66]. 

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