+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center



Inhibitory plant serpins with a sequence of three glutamine residues in the reactive center



Biological Chemistry 386(12): 1319-1323



Serpins appear to be ubiquitous in eukaryotes, except fungi, and are also present in some bacteria, archaea and viruses. Inhibitory serpins with a glutamine as the reactive-center P1 residue have been identified exclusively in a few plant species. Unique serpins with a reactive center sequence of three Gln residues at P3-P1 or P2-P1' were isolated from barley and wheat grain, respectively. Barley BSZ3 was an irreversible inhibitor of chymotrypsin, with a second-order association rate constant for complex formation k(a)' of the order of 10(4) M(-1) s(-1); however, only a minor fraction of the serpin molecules reacted with chymotrypsin, with the majority insensitive to cleavage in the reactive center loop. Wheat WSZ3 was cleaved specifically at P8 Thr and was not an inhibitor of chymotrypsin. These reactive-center loops may have evolved conformations that are optimal as inhibitory baits for proeinases that specifically degrade storage prolamins containing Gln-rich repetitive sequences, most likely for digestive proteinases of insect pests or fungal pathogens that infect cereals. An assembled full-length amino acid sequence of a serpin expressed in cotton boll fiber (GaZ1) included conserved regions essential for serpin-proteinase interaction, suggesting inhibitory capacity at a putative reactive center P2-P2' with a sequence of four Gln residues.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 004443546

Download citation: RISBibTeXText

PMID: 16336127

DOI: 10.1515/bc.2005.150


Related references

Inhibitory serpins from rye grain with glutamine as P1 and P2 residues in the reactive center. FEBS Letters 488(3): 149-153, 2001

Inhibitory serpins from wheat grain with reactive centers resembling glutamine-rich repeats of prolamin storage proteins. Cloning and characterization of five major molecular forms. Journal of Biological Chemistry 275(43): 33272-9, 2000

Significance of secondary structure predictions on the reactive center loop region of serpins: A model for the folding of serpins into a metastable state. FEBS Letters 383(1-2): 87-92, 1996

Serpins in fruit and vegetative tissues of apple (Malus domestica): expression of four serpins with distinct reactive centres and characterisation of a major inhibitory seed form, MdZ1b. Functional Plant Biology 32(6): 517-527, 2005

Mobile reactive center of serpins and the control of thrombosis. Nature (London) 353(6344): 576-578, 1991

Crystal structure of ovalbumin as a model for the reactive center of serpins. Nature (London) 347(6288): 99-102, 1990

A proton nmr probe for mobility in the reactive center loops of serpins. Biophysical Journal 61(2 Part 2): A324, 1992

Mutually exclusive exon use and reactive center diversity in insect serpins. Journal of Biological Chemistry 269(1): 55-58, 1994

Inhibitory mechanism of serpins. Mobility of the C-terminal region of the reactive-site loop. Journal of Biological Chemistry 272(7): 3905-3909, 1997

Serpins of oat (Avena sativa) grain with distinct reactive centres and inhibitory specificity. Physiologia Plantarum 116(2): 155-163, 2002

Structure of the reactive center loop of serpins implications for heparin antithrombin interactions. Journal of Cellular Biochemistry Suppl. (15 Part G): 104, 1991