Modulation of inhibitory activity of xylanase - α-amylase inhibitor protein (XAIP): binding studies and crystal structure determination of XAIP- II from Scadoxus multiflorus at 1.2 Å resolution

Kumar, Sanjit; Singh, Nagendra; Mishra, Biswajit; Dube, Divya; Sinha, Mau; Singh, S. Baskar; Dey, Sharmistha; Kaur, Punit; Sharma, Sujata; Singh, Tej P.
January 2010
BMC Structural Biology;2010, Vol. 10, p41
Academic Journal
Background: Plants produce a wide range of proteinaceous inhibitors to protect themselves against hydrolytic enzymes. Recently a novel protein XAIP belonging to a new sub-family (GH18C) was reported to inhibit two structurally unrelated enzymes xylanase GH11 and α-amylase GH13. It was shown to inhibit xylanase GH11 with greater potency than that of α-amylase GH13. A new form of XAIP (XAIP-II) that inhibits α-amylase GH13 with a greater potency than that of XAIP and xylanase GH11 with a lower potency than that of XAIP, has been identified in the extracts of underground bulbs of Scadoxus multiflorus. This kind of occurrence of isoforms of inhibitor proteins is a rare observation and offers new opportunities for understanding the principles of protein engineering by nature. Results: In order to determine the structural basis of the enhanced potency of XAIP-II against α-amylase GH13 and its reduced potency against xylanase GH11 as compared to that of XAIP, we have purified XAIP-II to homogeneity and obtained its complete amino acid sequence using cloning procedure. It has been crystallized with 0.1 M ammonium sulphate as the precipitating agent and the three-dimensional structure has been determined at 1.2 Å resolution. The binding studies of XAIP-II with xylanase GH11 and α-amylase GH13 have been carried out with surface plasmon resonance (SPR). Conclusion: The structure determination revealed that XAIP-II adopts the well known TIM barrel fold. The xylanase GH11 binding site in XAIP-II is formed mainly with loop α3-β3 (residues, 102 - 118) which has acquired a stereochemically less favorable conformation for binding to xylanase GH11 because of the addition of an extra residue, Ala105 and due to replacements of two important residues, His106 and Asn109 by Thr107 and Ser110. On the other hand, the α-amylase binding site, which consists of α-helices α6 (residues, 193 - 206), α7 (residues, 230 - 243) and loop β6-α6 (residues, 180 - 192) adopts a stereochemically more favorable conformation due to replacements of residues, Ser190, Gly191 and Glu194 by Ala191, Ser192 and Ser195 respectively in α-helix α6, Glu231 and His236 by Thr232 and Ser237 respectively in α-helix α7. As a result, XAIP-II binds to xylanase GH11 less favorably while it interacts more strongly with α-amylase GH13 as compared to XAIP. These observations correlate well with the values of 4.2 × 10-6 M and 3.4 × 10-8 M for the dissociation constants of XAIP-II with xylanase GH11 and α-amylase GH13 respectively and those of 4.5 × 10-7 M and 3.6 × 10-6 M of XAIP with xylanase GH11 and α-amylase GH13 respectively.


Related Articles

  • Filamentous Marine Fungi as Producers of O-Glycosylhydrolases: β-1,3-Glucanase from Chaetomium indicum. Yu. V. Burstseva, G.; Verigina, N.S.; Sova, V.V.; Pivkin, M.V.; Zvyagintseva, T.N. // Marine Biotechnology;Jul2003, Vol. 5 Issue 4, p349 

    Ninety fungal strains (42 species) isolated from marine habitats were studied for their ability to produce extracellular enzymes. Cultural filtrates of these strains were shown to contain a series of glycosidases (β-glucosidases, N-acetyl-β-glucosaminidases, β-galactosidases...

  • ENZYME CHANGES IN THE PLASMA AND PERITONEAL EXUDATE OF THE RAT FOLLOWING PANCREATIC DUCT OBSTRUCTION. Herriot, B. A.; Palmer, A. A. // Australian Journal of Experimental Biology & Medical Science;Feb1964, Vol. 42 Issue 1, p27 

    Looks into the changes in titre of serum amylase, serum lipase and peritoneal exudate amylase in response to pancreatitis. Occurrence of the rupture of small intrapancreatic ducts together with inflammatory cell infiltration; Correlation between peritoneal exudate amylase and plasma amylase in...

  • Microbial xylanases and their industrial applications: a review. Beg, Q. K.; Kapoor, M.; Maajan, L.; Hoondal, G. S. // Applied Microbiology & Biotechnology;Aug2001, Vol. 56 Issue 3/4, p326 

    Despite an increased knowledge of microbial xylanolytic systems in the past few years, further studies are required to achieve a complete understanding of the mechanism of xylan degradation by microorganisms and their enzymes. The enzyme system used by microbes for the metabolism of xylan is the...

  • Peptide Inhibitors of a-Amylase Based on Tendamistat: Development of Analogues with ?-Amino Acids Linking Critical Binding Segments. Heyl, Deborah L.; Tobwala, Shakila; Lucas, Leo Solomon; Nandanie, A. Dammika; Himm, Rebecca W.; Kappler, Jennifer; Blaney, Elizabeth J.; Groom, Jason; Asbill, Jeffrey; Nzoma, Jonathan K.; Jarosz, Cara; Palamma, Hanna; Schullery, Stephen E. // Protein & Peptide Letters;Apr2005, Vol. 12 Issue 3, p275 

    Peptide analogues of Tendamistat which include the most essential residues linked by novel w-amino acids (X,Y,Z: H2N-(CH2)n-CO2H, where n=2-10) were designed, synthesized (Ac-Tyr15-X-Trp18-Arg19-Tyr20-Y-Thr55-Z-Asp58- Gly59-Tyr60-Ile61-Gly62-NH2), and analyzed for a-amylase inhibitory activity....

  • In vitro and in vivo inhibition of a-amylases of stored-product mite Acarus siro. Jan Hubert; Lucie Doleckov-Mareov; Jana Hblov; Iva Kudlkov; Vclav Stejskal; Michael Mare // Experimental & Applied Acarology;2005, Vol. 35 Issue 4, p281 

    Abstract. The stored-product mites are the most abundant and frequent group of pests living on the stored food products in Europe. They endanger public health since they produce allergens and transmit mycotoxin-producing fungi. Novel acaricidal compounds with inhibitory effects on the digestive...

  • Amylase. Reynolds, Tim M. // British Journal of Hospital Medicine (17508460);Jan2009, Vol. 70 Issue 1, pM8 

    The article offers information on the attributes and significance of amylase to a person's body in Great Britain. These is a group of enzymes which is responsible for the proper breakdown of starches into sugars and the primary sources of these enzymes in human beings are salivary glands and...

  • Production of amylase by Arthrobacter psychrolactophilus. Smith, Michael R.; Zahnley, James C. // Journal of Industrial Microbiology & Biotechnology;Jul2005, Vol. 32 Issue 7, p277 

    Arthrobacter psychrolactophilus ATCC 700733 grew with a doubling time of 1.5�2.3 h (22�C) and produced up to 0.2 units/mL (soluble starch assay) of extracellular amylase in tryptic soy broth without dextrose (TSBWD) containing 0.5% or 1.0% (w/v) soluble starch or maltose as the...

  • Effect of a High Dose of Ethanol on Serum Pancreatic Enzymes in Young Healthy Adults. Jaakkola, Mika; Sillanaukee, Pekka; Suomalainen, Hanna; Koivula, Timo; Nordback, Isto // American Journal of Gastroenterology;Apr1992, Vol. 87 Issue 4, p461 

    Short-term effects of a high dose of ethanol on the serum activities of pancreatic enzymes were studied in young healthy adults. There were 10 males and 10 females in the study group, and two males and three females in the control group. In the study group, ethanol (2 g/kg of body weight) was...

  • Amylase Excretion after Exercise. Cucinell, Samuel A.; Shaw Wan; O'Brien, John; Wade, Charles // American Journal of Gastroenterology;Aug1984, Vol. 79 Issue 8, p619 

    Increase in amylase excretion in the urine in response to 8 days of aerobic running is delayed until after the athletes have rested for 24-48 h. In contrast, the amylase creatinine ratio is increased immediately after intense short-term exercise. The mechanism for these differences is unknown,...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics