Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pancreatic amylase, chymotrypsin B, and trypsin I genes are specifically expressed in the exocrine pancreas. The 5'-flanking regions of these genes direct preferential expression of a linked reporter function (chloramphenicol acetyltransferase) in the pancreatic exocrine cell line AR4-2J. The sequences upstream of the amylase and chymotrypsin genes that are required for this cell specific activity possess the characteristics of transcriptional enhancers. We have mapped the regions responsible for enhancer activity by deletion analysis. Modification of specific nucleotide sequences within these regions can alter or eliminate enhancer function. Comparison of the 5'-flanking regions of nine genes expressed in the exocrine pancreas identifies a family of short related sequences. These sequences are located within the enhancer regions that we have mapped and may play a role in the regulation of the expression of pancreatic exocrine-specific genes.
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PMID:Cell-specific enhancers in the rat exocrine pancreas. 242 7

A family of approximately 10 trypsin genes was detected in a rat genomic library by hybridization and in vivo recombination techniques using cloned rat pancreatic trypsin I and II cDNAs as probes. Two separate clones containing the entire trypsin I gene and most of the trypsin II gene were sequenced. Four introns split the trypsin I coding sequence. The positions of the first three introns of the trypsin II gene are identical with those in the trypsin I gene (the fourth intron was not present in the trypsin II clone). The coding regions of the two genes are 88% homologous; the 5'-noncoding regions are 92% homologous, whereas the 3'-noncoding regions share 66% identity. In contrast, the proximal 5'-flanking regions from -1 to -500 which may contain the elements controlling gene expression are less than 30% conserved overall, but segments of approximately 70% homology can be discerned in this region. Some of these sequences are homologous to sequences found in the chymotrypsin and elastase genes. More distal upstream sequences (-500 to -2500) and the intervening sequences show no evident sequence homology (less than 20%). Unique sequences containing homopolymeric purine/pyrimidine repeats are found 2.5 kilobases upstream from the start of transcription of the trypsin I gene and within the second and third introns of the trypsin II gene. The nucleotide homologies as well as the similarities of intron positions of the two trypsin genes to those of other serine protease genes clearly support an evolutionary relationship between members of this gene family.
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PMID:Structure of two related rat pancreatic trypsin genes. 609 47

We have isolated and characterized rat genomic DNA fragments bearing the two secretory elastase genes that are expressed in the exocrine pancreas. The complete exonic sequences for each of the genes as well as considerable intronic and flanking sequences are reported. Each elastase gene is interrupted by seven intervening sequences which are located at corresponding positions within the two genes, with one exception: the third intron of the elastase II gene has shifted one codon in the 5' direction. The placement of introns within the amino acid coding domains in part may reflect the formation of the progenitor serine protease gene by the duplication of an exon encoding a characteristic polypeptide structure comprising three beta sheets. The activation peptides of the zymogens and the signal peptides, which form discrete functional domains in the protein precursors, are encoded by separate exons. In addition to the TATAA box, the two genes share considerable sequence similarity in the 5'-proximal flanking regions (up to approximately 450 base pairs upstream); however, a number of gaps must be introduced to optimize the sequence alignment. The similarities are largely confined to six oligonucleotide regions with greater than 70% sequence conservation. The elastase I gene has a perfect repeating copolymer (GT)24 located 427-379 nucleotides upstream from the start of transcription. The elastase II gene has a similar GT-rich region (52/55 G or T) located 384-330 nucleotides upstream. Comparison of the 5'-flanking regions of the two elastase genes with those of pancreatic chymotrypsin and trypsin I and II reveals that one of the six conserved oligonucleotide regions is generally conserved for these genes as well. This conserved region contains putative enhancer core sequences.
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PMID:Structure of the two related elastase genes expressed in the rat pancreas. 609 48

The present work describes the effect of two soya bean protease inhibitors: Kunitz type (SBTI) and Bowman-Birk type (BBTI) on rat trypsin I (TrI), trypsin II (TrII) and chymotrypsin (Chtr) and on human cationic trypsin (hTr). The inhibition spectra show that: (1) SBTI inhibits TrI, TrII, Chtr and hTr esterase activities by 80, 80, 83 and 45%, respectively, at inhibitor-to-enzyme molar ratios of one-to-one, and (2) BBTI inhibits TrI, TrII, Chtr, and hTr esterase activities by 50, 65, 75 and 30%, respectively, at an inhibitor-to-enzyme molar ratio of two-to-one. A similar inhibition pattern was obtained by testing proteolytic activities. It would appear that hTr is less sensitive to soya bean protease inhibitors than each of the rat proteases investigated. This difference in inhibition should be considered when a rat is used as a model to predict the effects of dietary soya bean protease inhibitors on humans.
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PMID:Comparison of the interactions of soya bean protease inhibitors with rat pancreatic enzymes and human trypsin. 661 23