A Comparative Study on Amino Acid Sequences of Three Major Isoforms of Human Pepsin A

Tarasova, Nadezhda I.; Denslow, Nancy D.; Parten, Benne F.; Tran, Nha; Nhuyen, Hung P.; Jones, Arwyn Tomos; Roberts, Norman B.; Dunn, Ben M.

doi:10.1007/978-1-4615-1871-6_8

Cited by 6 publications

(5 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Phosphorylase b sequence coverage was 88% and 64% for PG-1 and PG-2, respectively (see Supplemental Figure S4; data for PG-3 not shown). As aspartic proteases often have isoforms (e.g., human pepsin A has three isoforms, A1, A2, A3[40], Antarctic rock cod has two isoforms [21]), perhaps such differences as observed for rice field eel pepsin exist for other species in terms of variation in activity and specificity between isoforms.…”

Section: Resultsmentioning

confidence: 99%

Accessing the reproducibility and specificity of pepsin and other aspartic proteases

Ahn

Cao

et al. 2013

Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics

123

107

View full text Add to dashboard Cite

The aspartic protease pepsin is less specific than other endoproteinases. Because aspartic proteases like pepsin are active at low pH, they are utilized in hydrogen deuterium exchange mass spectrometry (HDX MS) experiments for digestion under hydrogen exchange quench conditions. We investigated the reproducibility, both qualitatively and quantitatively, of online and offline pepsin digestion to understand the compliment of reproducible pepsin fragments that can be expected during a typical pepsin digestion. The collection of reproducible peptides was identified from >30 replicate digestions of the same protein and it was found that the number of reproducible peptides produced during pepsin digestion becomes constant above 5-6 replicate digestions. We also investigated a new aspartic protease from the stomach of the rice field eel (Monopterus albus Zuiew) and compared digestion efficiency and specificity to porcine pepsin and aspergillopepsin. Unique cleavage specificity was found for rice field eel pepsin at arginine, asparagine, and glycine. Different peptides produced by the various proteases can enhance protein sequence coverage and improve the spatial resolution of HDX MS data.

show abstract

Section: Resultsmentioning

confidence: 99%

Accessing the reproducibility and specificity of pepsin and other aspartic proteases

Ahn

Cao

et al. 2013

Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics

123

107

View full text Add to dashboard Cite

show abstract

“…Human pepsin was obtained from stomach mucosa, essentially as described previously (Tarasova et al, 1994). Stomachs were obtained during dissection no later than 3 h after death certification and kept at -70 "C before use.…”

Section: Methodsmentioning

confidence: 99%

“…Human pepsin is known to consist of up to four isoforms with differing enzymatic properties (Tarasova et al, 1994). The reported substitutions of Gln 160 to Lys, Asn 230 to Lys, and Ala 203 to Thr are not likely to modify the specificity of pepsin because these changes are located far from the binding sites.…”

Section: Other Isoformsmentioning

confidence: 99%

Crystal structure of human pepsin and its complex with pepstatin

et al. 1995

View full text Add to dashboard Cite

The three-dimensional crystal structure of human pepsin and that of its complex with pepstatin have been solved by X-ray crystallographic methods. The native pepsin structure has been refined with data collected to 2.2 A resolution to an R-factor of 19.7%. The pepsin:pepstatin structure has been refined with data to 2.0 A resolution to an R-factor of 18.5%. The hydrogen bonding interactions and the conformation adopted by pepstatin are very similar to those found in complexes of pepstatin with other aspartic proteinases. The enzyme undergoes a conformational change upon inhibitor binding to enclose the inhibitor more tightly. The analysis of the binding sites indicates that they form an extended tube without distinct binding pockets. By comparing the residues on the binding surface with those of the other human aspartic proteinases, it has been possible to rationalize some of the experimental data concerning the different specificities. At the S1 site, valine at position 120 in renin instead of isoleucine, as in the other enzymes, allows for binding of larger hydrophobic residues. The possibility of multiple conformations for the P2 residue makes the analysis of the S2 site difficult. However, it is possible to see that the specific interactions that renin makes with histidine at P2 would not be possible in the case of the other enzymes. At the S3 site, the smaller volume that is accessible in pepsin compared to the other enzymes is consistent with its preference for smaller residues at the P3 position.

show abstract

“…There are at least seven enzymes produced by the human, shown by differing mobility on agar gel electrophoresis. The enzymes possess a strong overall negative charge because of the relatively large amount of aspartic and glutamic amino acid residues 6, 7 and are separated at pH 5.0 by their relative mobility to the anode. The numbering adopted was developed on the components that migrated furthest being called 1 and the slowest up to the number of zones visualized, 8 Figure 1.…”

Section: Visualization and Nomenclaturementioning

confidence: 99%

Review article: human pepsins – their multiplicity, function and role in reflux disease

Roberts

2006

Aliment Pharmacol Ther

View full text Add to dashboard Cite

Summary Human gastric juice contains a multiplicity of proteinases. These are classified as aspartic proteinases because of enzymic activity dependent on two oppositely placed aspartic acids in the active site region. At least seven zones of activity can be visualized by agar gel electrophoresis and a similar number of separate proteins resolved by high performance ion exchange chromatography. The major enzyme secreted (up to 70% of the total) pepsin 3b is sensitive to the selective inhibitor pepstatin whereas gastricsin or pepsin 5 (20% of the total) is not. Minor enzymes including pepsin 1, which has an associated proteincarbohydrate complex attached is variable and can be <5% in normal and up to 20% of the total as in peptic ulcer patients. The activity of these enzymes depends on the substrate and pH with significant digestion occurring up to pH 4.5. It has also been shown that these enzymes can bind to substrates like collagen up to pH 5.5. In gastric secretion studies of patients with reflux oesophagitis the amount of pepsin and the profile of the enzymes in basal secretions, and that after pentagastrin stimulation, was found to be not different from healthy non‐refluxers. Thus the problem with reflux is that gastric juice appears in the oesophagus, an area without any natural protection from proteolytic damage. The ability to reduce gastric secretion is therefore important in effective treatment. However, being able also to inhibit enzymic activity or protect substrates from damage using alginates offers considerable scope for future therapies.

show abstract

A Comparative Study on Amino Acid Sequences of Three Major Isoforms of Human Pepsin A

Cited by 6 publications

References 4 publications

Accessing the reproducibility and specificity of pepsin and other aspartic proteases

Accessing the reproducibility and specificity of pepsin and other aspartic proteases

Crystal structure of human pepsin and its complex with pepstatin

Review article: human pepsins – their multiplicity, function and role in reflux disease

Contact Info

Product

Resources

About