Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0235108 (tense)
 2,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied a case of severe infantile mucolipidosis that fell within the clinical spectrum of mucolipidosis I. A 2,100-g girl was delivered by cesarean section at 30 weeks' gestation, after the development of polyhydramnios. Tense ascites and hepatomegaly were present at birth and persisted until her death at age 4 months. Although she was growth retarded, no dysmorphic features were evident. Mucopolysacchariduria was absent, and no lysosomal enzyme deficiencies were identified in cultures of fibroblasts. N-acetyl neuraminidase was not included in the assay. Excessive intracellular accumulation of material within membrane-bound vacuoles was demonstrated in all tissues examined by light and electron microscopy. This material had histochemical and ultrastructural characteristics of both mucopolysaccharides and lipids. The placental trophoblasts, hepatocytes, neurons, glomerular epithelium, and mononuclear phagocytes were most affected.
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PMID:A severe infantile mucolipidosis. Clinical, biochemical, and pathologic features. 668 32

Statistically significant charge clusters (basic, acidic, or of mixed charge) in tertiary protein structures are identified by new methods from a large representative collection of protein structures. About 10% of protein structures show at least one charge cluster, mostly of mixed type involving about equally anionic and cationic residues. Positive charge clusters are very rare. Negative (or histidine-acidic) charge clusters often coordinate calcium, or magnesium or zinc ions [e.g., thermolysin (PDB code: 3tln), mannose-binding protein (2msb), aminopeptidase (1amp)]. Mixed-charge clusters are prominent at interchain contacts where they stabilize quaternary protein formation [e.g., glutathione S-transferase (2gst), catalase (8act), and fructose-1,6-bisphosphate aldolase (1fba)]. They are also involved in protein-protein interaction and in substrate binding. For example, the mixed-charge cluster of aspartate carbamoyl-transferase (8atc) envelops the aspartate carbonyl substrate in a flexible manner (alternating tense and relaxed states) where charge associations can vary from weak to strong. Other proteins with charge clusters include the P450 cytochrome family (BM-3, Terp, Cam), several flavocytochromes, neuraminidase, hemagglutinin, the photosynthetic reaction center, and annexin. In each case in Table 2 we discuss the possible role of the charge clusters with respect to protein structure and function.
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PMID:Clusters of charged residues in protein three-dimensional structures. 871 Aug 74