Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The results from molecular mass determinations and amino acid analyses for prostate-specific antigen (PSA), alpha 1-antichymotrypsin (ACT) and PSA-ACT complexed in vitro are reported. Molecular masses for two separate PSA-ACT lots were determined by matrix-assisted laser desorption ionization mass spectroscopy (MALDI-MS) coupled to a time-of-flight (TOF) detector. Interestingly, both PSA-ACT lots contained two predominant protein species: 78,095 +/- 138 Da (approx. 67% of total protein) and 82,519 +/- 104 Da. Because a heterogneous population was observed and the masses were less than expected on the basis of less sensitive techniques, molecular masses for the individual PSA and ACT components were determined. As expected, PSA possessed a single molecular mass (27,755.8 Da). Each ACT raw material lot, however, also contained two predominant species: 55,106 +/- 111 and 51,414 +/- 32 Da. To assess the amino acid composition, each PSA, ACT and PSA-ACT lot was subjected to acid hydrolysis for 24, 48 and 72 h followed by amino acid analysis. Experimental results, expressed as mole percentages for each measurable residue and the number of residues per mole of protein, were compared with both the predicted and previously published values and were as expected. These more accurate molecular mass values for ACT and purified PSA-ACT complex should be considered in preparing and characterizing international standard preparations.
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PMID:Molecular mass determination for prostate-specific antigen and alpha 1-antichymotrypsin complexed in vitro. 966 80

Human kallikrein 2 (hK2) is a serine protease expressed predominantly in the prostate which has 80% homology to prostate-specific antigen (PSA). hK2 is an active trypsin-like protease which has been shown by immuno-histochemical staining to be more highly expressed in prostate carcinoma than in benign prostate tissue. Unlike PSA, hK2 activates pro-PSA , pro-hK2 and the zymogen form of urokinase-type plasminogen activator (uPA), an extracellular protease correlated with prostate cancer and metastasis. We show here that hK2 rapidly forms a complex with plasminogen activator inhibitor-1 (PAI-1), the primary inhibitor of uPA in tissues. In addition, hK2 inactivated 6 to 7 mol of PAI-1 by cleavage at Arg346-Met347 for every mole of hK2-PAI-1 complex formed. In contrast with hK2, PSA neither complexed with nor inactivated PAI-1. PAI-1 inhibited hK2 comparably with protein C inhibitor (PCI) and at least 20 times more rapidly than alpha1-anti-chymotrypsin (ACT). N-Terminal sequencing shows that hK2 forms a covalent complex with PAI-1, PCI and ACT after cleavage at Arg346-Met347, Arg354-Ser355 and Leu358-Ser359, respectively. During complex formation, hK2 inactivated PAI-1 but did not inactivate ACT or PCI. Our current results suggest that the increased hK2 expression in prostate cancer tissues could influence cancer biology not only by activation of uPA but also by inactivation of its primary inhibitor, PAI-1.
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PMID:Prostatic human kallikrein 2 inactivates and complexes with plasminogen activator inhibitor-1. 1020 59

There is growing evidence that risk factors for cancer occurrence and for cancer death are not necessarily the same. Knowledge of cancer aggressiveness risk factors (CARF) may help in identifying subjects at high risk of developing a potentially deadly cancer (and not just any cancer). The availability of CARFs may have positive consequences for health policies, medical practice, and the search for biomarkers. For instance, cancer chemoprevention and cancer screening of subjects with CARFs would probably be more ethical and cost-effective than recommending chemoprevention and screening to entire segments of the population. Also, the harmful consequences of chemoprevention and of screening would be reduced while effectiveness would be optimised. We present examples of CARF already in use (e.g. mutations of the breast cancer (BRCA) gene), of promising avenues for the discovery of biomarkers thanks to the investigation of CARFs (e.g. breast radiological density and systemic inflammation), and of biomarkers commonly used that are not real CARFs (e.g. certain mammography images, prostate-specific antigen (PSA) concentration, nevus number).
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PMID:Risk factors and biomarkers of life-threatening cancers. 2663