Molecular cloning, expression, and cytokinin (6-benzylaminopurine) antagonist activity of peanut (Arachis hypogaea) lectin SL-I

Monika Pathak, Bharat Singh, Amit Sharma, Praveen Agrawal, Santosh B. Pasha, Hasi R. Das, Rakha H. Das

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

Isolation and purification of a α-methyl-mannoside specific lectin (SL-I) of peanut was reported earlier [Singh and Das (1994) Glycoconj J 11:282-285]. Native SL-I is a glycoprotein having ∼31 kDa subunit molecular mass and forms dimer. The gene encoding this lectin is identified from a 6-day old peanut root cDNA library by anti-SL-I antibody and N-terminal amino acid sequence homology to the native lectin. Nucleotide sequence derived amino acid sequence of the re-SL-I shows amino acid sequence homology with the N-terminal and tryptic digests' amino acid sequence of the native SL-I (nSL-I). Presence of a putative glycosylation (QNPS) site and a hydrophobic adenine-binding (VLVSYDANS) site is also identified in SL-I. Homology modeling of the lectin suggests it to be an archetype of legume lectins. It is expressed as a ∼30 kDa apoprotein in E. coli and has the carbohydrate specificity and secondary structure identical to its natural counterpart. The lectin SL-I inhibits cytokinin 6-benzylaminopurine (BA)-induced "delayed leaf senescence" and "cotyledon expansion". Equilibrium dialysis revealed a single high-affinity binding site for adenine (7.6 × 10-6 M) and BA (1.09 × 10-5 M) in the SL-I dimer and thus suggesting that the cytokinin antagonist effect of SL-I is mediated by the direct interaction of SL-I with BA.

Original languageEnglish (US)
Pages (from-to)529-545
Number of pages17
JournalPlant Molecular Biology
Volume62
Issue number4-5
DOIs
StatePublished - Nov 2006
Externally publishedYes

Keywords

  • Cytokinin 6-benzylaminopurine
  • Cytokinin antagonist activity
  • Gene expression
  • Peanut lectin SL-I

ASJC Scopus subject areas

  • Genetics
  • Agronomy and Crop Science
  • Plant Science

Fingerprint

Dive into the research topics of 'Molecular cloning, expression, and cytokinin (6-benzylaminopurine) antagonist activity of peanut (Arachis hypogaea) lectin SL-I'. Together they form a unique fingerprint.

Cite this