The molecular biology and biochemistry of rice endosperm. alpha. -globulin

Miscellaneous · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5672224

Shorrosh, B S

The author's first objective was to isolate a cDNA clone that encodes the rice endosperm {alpha}-globulin. Purified antibodies against a rice storage protein, {alpha}-globulin, were used to screen a {lambda}gt11 cDNA expression library constructed from immature rice seed endosperm. The cDNA insert of clone 4A1 (identified by antibody screening) was used as a probe to identify long cDNA inserts in the library. The deduced amino acid sequence of clone A3-12 cDNA insert (identified by cDNA screening) contained the amino acid sequences of three cyanogen bromide peptides fragment of {alpha}-globulin. The calculated molecular weight and amino acid composition of the deduced amino acid sequence were similar to the {alpha}-globulin protein. Northern blot analysis indicated that mRNA of one size, approximately 1.0 kb, is expressed. Southern genomic blot analysis revealed one band with EcoRI or Hind III digestion. Cell-free translation and immunoprecipitation showed that the initial translation product is approximately 2,000 daltons larger than the mature protein. The amino acid sequence of {alpha}-globulin revealed limited regions of similarities with wheat storage proteins. The author concludes that the cDNA insert in clone A3-12 contained the entire coding region of {alpha}-globulin protein and that {alpha}-globulin is encoded by a single gene. My second objective was to inhibit the degradation of {alpha}-globulin in the salt extract of rice flour. The salt extract of rice flour contained an acid protease whose optimal pH was 3 for {sup 3}H-casein hydrolysis. A polypeptide with molecular weight of 20,000 was immunologically reactive with {alpha}-globulin antibodies and is produced by limited proteolysis in the extract. Pepstatin inhibited the proteolysis of 3H-casein and slowed the proteolysis of {alpha}-globulin.

• Research Organization: Kansas State Univ., Manhattan, KS (USA)
• OSTI ID: 5672224
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CASEIN
METABOLISM
GLOBULINS
GENES
RICE
BIOCHEMISTRY
AMINO ACID SEQUENCE
DNA
IMMUNOASSAY
MESSENGER-RNA
MOLECULAR BIOLOGY
MOLECULAR WEIGHT
TRACER TECHNIQUES
TRITIUM COMPOUNDS
BIOASSAY
CEREALS
CHEMISTRY
GRAMINEAE
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LILIOPSIDA
MAGNOLIOPHYTA
MOLECULAR STRUCTURE
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PLANTS
PROTEINS
RNA
550201* - Biochemistry- Tracer Techniques
550501 - Metabolism- Tracer Techniques