Amino acid sequence of serine protease inhibitor CI-1 from barley. Homology with barley inhibitor CI-2, potato inhibitor I, and leech eglin

Abstract

The inhibitor (CI-1) is homologous with another barley inhibitor (CI-2), with potato inhibitor I and with the elastase-cathepsin G inhibitor eglin from the leech Hirudo medicinalis (30-50% of the amino acid residues in identical positions). This established >ffamily of cystine-independent inhibitors(t also showed some sequence similarities with the cystine-free yeast proteinase B inhibitors I and 2. In the reactive site region homologies with the cystine-rich inhibitors of the ,Kazal pancreas secretory inhibitort~ and the >>Streptomyces subtilisin inhibitor~ families were observed.Abbreviations: APNE = N-acetyl-o,L-phenylalanine-2-naphtylester; CI-1 and CI-2 = chymotrypsin inhibitor I and 2 from barley (3); LIE = Leech inhibitor eglin (17); PI-I = potato inhibitor [ (15); Polybrene = hexadimethrine bromide; PTH = phenylthiohydantoin; SDS = sodium dodecyl sulfate; THEED = N,N,N',N',-tetrakis (2-hydroxyethyl)ethylenediamine; YIB = yeast inhibitor of protease B (ll).

A new protein inhibitor of trypsin and activated hageman factor from pumpkin (Cucurbita maxima) seeds

“…The structure of CMTI-V shows clear and strong sequence similarities with the potato I iso-inhibitors [20-221, inhibitors from tomato leaves [23], barley [24], bean 1251 and also with the leech inhibitor eglin [26]. It should be noted that other workers have previously reported a trypsin inhibitor from seeds of Momordica chmzntia (Cucurbitaceae) which also had a weak homology with the members of the potato I family 1271.…”

The amino acid sequence of a trypsin inhibitor from the seeds of Momordica charantia Linn. Cucurbitaceae

“…In the comparable part of the sequences (residues 27-88), 18%, 18%, 21%, 25% of the residues in MCI-3 were found in the same positions in LIE, PI-l, VSI and CI-2, respectively. These identical ; CI-2, chymotrypsin inhibitor-2 from barley [9]; LIE, the leech inhibitor eglin [8]; PI-I, potato inhibitor-I (71. Invariant amino acid residues are boxed; (--) indicates gaps introduced to maximize homology.…”

“…MCI-3 may also belong to the 'potato inhibitor I family'. This family of inhibitors is as far as we know functionally independent of the presence of disulfide bridges in their structures [9]. DABTH , 4-N,N-dimethylaminoazobenzene-4.…”

The amino acid sequence of a cereal Bowman‐Birk type trypsin inhibitor from seeds of Jobs' tears (Coix lachryma‐jobi L.)

“…For example the a-amylase inhibitors from wheat [2][3][4], and rye [5], proteinase inhibitors from rye [5], barley [6] and maize [7], and a hifunctional a-amylase/trypsin inhibitor from ragi [8] belong to a so-called superfamily [9] which also includes the cereal chloroform-methanol (CM) soluble proteins and certain 2 S storage proteins from dicotyledonous plants. Other bifunctional inhibitors from barley [10,11], wheat [12,13] Correspondence address: M. Richardson, Department of Botany, University of Durham, Science Laboratories, South Road, Durham DHI 3LE, England and rice [14] have sequence homology with the legume Kunitz inhibitor family, while proteinase inhibitors from barley [15,16] clearly belong to the potato inhibitor 1 family. The sequences of probable tr-amylase/proteinase inhibitors from barley [17,18] and rice [19] suggest that they should be included with the ragi I-2 a-amylase inhibitor [20] as a separate family.…”