z-logo
open-access-imgOpen Access
A Major Gibberellic Acid-Induced Barley Aleurone Cysteine Proteinase Which Digests Hordein
Author(s) -
Susan M. Koehler,
TuanHua David Ho
Publication year - 1990
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.94.1.251
Subject(s) - hordein , aleurone , hordeum vulgare , leupeptin , biochemistry , gel electrophoresis , protease , cysteine , cysteine proteinase inhibitors , isoelectric focusing , chemistry , amino acid , polyacrylamide gel electrophoresis , chromatography , biology , storage protein , enzyme , botany , poaceae , apoptosis , programmed cell death , caspase , gene
We previously described the purification and characterization of a 37,000 M(r) cysteine proteinase, designated EP-A, from gibberellic acid (GA(3))-induced barley (Hordeum vulgare L.) aleurone layers (S Koehler, T-HD Ho [1988] Plant Physiol 87: 95-103). A second, more abundant protease has now been purified from this tissue. This protease, designated EP-B, has an apparent M(r) of 30,000 on 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). It resolves into two bands during native isoelectric focusing with pl of 4.6 to 4.7. The analysis of hemoglobin digestion products by both gradient SDS-PAGE and Bio-Gel P2 chromatography, the inhibition of protease activity by E-64, leupeptin, iodoacetate, and p-hydroxymercuribenzoate, and N-terminal amino acid sequence analysis all indicate that EP-B is a cysteine proteinase. The first 22 amino acids at the N terminus of EP-B have been determined, and their sequence is 90% similar to that of EP-A. EP-B has properties similar to EP-A; however, EP-B is much more sensitive to high pH during gel electrophoresis and therefore is not detectable on native activity gels used to detect EP-A. Its pH optimum against azocasein and hemoglobin is 4.5 to 4.6. Both of these proteinases digest hordeins enriched for the B and D fractions into similar peptides of 25,000 to 2,000 M(r) as determined by gradient SDS-PAGE.

The content you want is available to Zendy users.

Already have an account? Click here to sign in.
Having issues? You can contact us here