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Articles 1 - 30 of 59

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Analysis Of Globulin-1 Promoter Activity And The Expression Of Gfp In Transgenic Maize Seed Tissues And Processing Of Gfp-Containing Grain, Colin Shepherd Jan 2007

Analysis Of Globulin-1 Promoter Activity And The Expression Of Gfp In Transgenic Maize Seed Tissues And Processing Of Gfp-Containing Grain, Colin Shepherd

Retrospective Theses and Dissertations

The maize (Zea mays L) kernel is perfectly configured to store proteins and nutrients. The major proteins of the maize kernel are known as seed storage proteins because they have no enzymatic function and they accumulate to a high level for use during germination of the seed as an immediate nutrient source. These seed storage proteins are responsible for much of the nutrient quality of maize when used as a food or feed source. Understanding the regulation of seed storage protein deposition may allow researchers to improve the use of maize grain in a variety of food and feed products ...


Enhancement Of Plant Performance And Biochemical Constituents In Field And Hairy Root Production Of Echinacea , Fredy Rolando Romero Orellana Jan 2006

Enhancement Of Plant Performance And Biochemical Constituents In Field And Hairy Root Production Of Echinacea , Fredy Rolando Romero Orellana

Retrospective Theses and Dissertations

Echinacea is a commercially important source of natural products and phytopharmaceuticals. Echinacea products currently constitute a significant portion of the rapidly growing, multi-billion dollar natural products market. This popularity has led to the expansion of commercial cultivation of Echinacea and the need to find alternative methods to meet the increasing demands of the phytopharmaceutical market. Two methods of producing biochemical constituents in commercial use include extraction from field-grown plants and in vitro hairy root production;Echinacea seeds in the wild typically show a high degree of dormancy. In order to enhance Echinacea seed germination for field production, alternative methods to ...


Phenotypic, Biochemical, And Molecular Diversity In Coriander (Coriandrum Sativum L) Germplasm, Pedro Antonio López Jan 2006

Phenotypic, Biochemical, And Molecular Diversity In Coriander (Coriandrum Sativum L) Germplasm, Pedro Antonio López

Retrospective Theses and Dissertations

A study was conducted to assess phenotypic, biochemical, and molecular diversity in coriander accessions from the North Central Regional Plant Introduction Station, in Ames, IA; initially, 139 accessions were characterized for phenological and morphological traits and for fatty-acid composition. A second year of data was collected on those traits from 60 accessions. Fruit essential-oil content and composition were determined, along with a headspace analysis from leaves and an analysis of amplified fragment length polymorphisms (AFLPs). Basic statistics and Pearson correlations were estimated. Matrices of geographical distances (GD), modified Rogers' (MD) distances for molecular data, and Euclidean distances for phenotypic (PD ...


Molecular Genetic Analyses Of Oilseed Brassica Germplasm: Determination Of Life Forms And Germplasm Management Strategies By Using Microsatellite Markers And Flowering Locus-C (Flc1 And Flc3) Gene Sequences , Von Mark V. Cruz Jan 2006

Molecular Genetic Analyses Of Oilseed Brassica Germplasm: Determination Of Life Forms And Germplasm Management Strategies By Using Microsatellite Markers And Flowering Locus-C (Flc1 And Flc3) Gene Sequences , Von Mark V. Cruz

Retrospective Theses and Dissertations

Molecular markers were utilized in conjunction with phenological and morphological information, and statistical methods for diversity analyses to address plant genetic resource conservation issues. The objectives of this study have been categorized into two sets. The first set pertains to exploratory surveys of genetic variation using molecular markers and DNA sequences to determine if microsatellite markers or variation in two copies of the FLOWERING LOCUS C gene (FLC1 and FLC3) can be used in determining life forms of fifty representative accessions of Brassica napus. The second set of objectives addresses good genebank practices and includes: characterization of flowering time of ...


Qtl Mapping And Gene Discovery In Perennial Ryegrass (Lolium Perenne L.) , Yanwen Xiong Jan 2005

Qtl Mapping And Gene Discovery In Perennial Ryegrass (Lolium Perenne L.) , Yanwen Xiong

Retrospective Theses and Dissertations

Perennial ryegrass (Lolium perenne L.) has been used extensively for both forage and turf in temperate regions. To understand the genetic basis of winter hardiness and forage quality and molecular basis of cold acclimation of ryegrass, we mapped quantitative trait loci (QTL) that control winter hardiness and forage quality by using an interspecific ryegrass population and identified a C&barbelow;-repeat (CRT)/dehydration-responsive element (DRE) b&barbelow;inding f&barbelow;actors (CBF)-like gene in perennial ryegrass. Winter hardiness related traits including fall growth (FG), freezing tolerance (FT), and winter survival (WS) were measured over two years. A total of twenty-six QTLs were ...


Sooty Blotch And Flyspeck On Apple: Expansion Of The Fungal Complex, Post-Harvest Removal And Heterogeneity Of Apple Canopy Wetness And Its Impact On The Outcome Of A Disease-Warning System , Jean Carlson Batzer Jan 2005

Sooty Blotch And Flyspeck On Apple: Expansion Of The Fungal Complex, Post-Harvest Removal And Heterogeneity Of Apple Canopy Wetness And Its Impact On The Outcome Of A Disease-Warning System , Jean Carlson Batzer

Retrospective Theses and Dissertations

Sooty blotch and flyspeck (SBFS) fungi blemish the cuticle of apples. Previous studies reported that the SBFS complex is comprised of four species. This is study surveyed the SBFS complex from nine orchards in four Midwestern states (USA). The LSU analyses of the rDNA inferred that 30 species were Dothideomycetes; one species was within the Pleosporales, 27 were within Dothideales, and two species could not be placed at the ordinal level. The LSU sequences of 17 Dothideales species clustered with LSU sequences of known species of Mycosphaerella. Post-harvest dips in commercial disinfestants were used to remove SBFS signs. Apples were ...


Genetic Basis Of Autumn Growth And Winter Hardiness In Alfalfa , Baldomero Alarcón Zúñiga Jan 2003

Genetic Basis Of Autumn Growth And Winter Hardiness In Alfalfa , Baldomero Alarcón Zúñiga

Retrospective Theses and Dissertations

Alfalfa (Medicago sativa L.) has a broad geographic distribution, with populations adapted to both cold and warm climates. Despite considerable research on winter hardiness, the mechanisms and genetic control of winter survival are poorly understood. We conducted two experiments designed to identify and quantify morphological, physiological, and biochemical traits associated with winter hardiness and to estimate the genetic relationship of these traits with winter hardiness. In Experiment 1, ten alfalfa genotypes were planted in June 2000 and in May 2001 at Ames, IA, and traits were measured in August, November, and the following April in each year. Concentrations of palmitate ...


Molecular Marker Analysis Of Population Genetic Structure And Progress From Reciprocal Recurrent Selection In Two Iowa Maize (Zea Mays L) Populations , Lori Lynn Hinze Jan 2003

Molecular Marker Analysis Of Population Genetic Structure And Progress From Reciprocal Recurrent Selection In Two Iowa Maize (Zea Mays L) Populations , Lori Lynn Hinze

Retrospective Theses and Dissertations

Studies of the genetic structure of the Iowa Corn Borer Synthetic #1 (CB) and Iowa Stiff Stalk Synthetic (SS) maize populations are of particular significance because they serve as the model on which development of modern commercial hybrids are based. These populations are part of a reciprocal recurrent selection breeding strategy. With this strategy, plants from one population are crossed to plants from the opposite population (i.e. forming hybrids). These hybrids are tested, and the best ones are chosen. The plants crossed to form the chosen hybrids are identified and used to form the next generation in each population ...


Molecular And Genetic Characterization Of The Inheritance And Expression Of The Synthetic Porcine Alpha-Lactalbumin Transgene In Maize (Zea Mays L) , Earl H. Bicar Jan 2003

Molecular And Genetic Characterization Of The Inheritance And Expression Of The Synthetic Porcine Alpha-Lactalbumin Transgene In Maize (Zea Mays L) , Earl H. Bicar

Retrospective Theses and Dissertations

A codon-adjusted version of a gene encoding the porcine milk protein alpha-lactalbumin was synthesized to create maize with improved nutritional quality. Three expression vectors (P64, P45, P57) containing the synthetic gene were constructed and transformed into maize callus by particle bombardment. The constructs differed in their promoters and subcellular targeting domains. PCR analysis showed that the alpha-La transgene was integrated into the maize genome and transmitted to the F1 generation. Western blot analysis indicated that the transgenes were functional and the alpha-La protein accumulated in the target endosperm. Genomic Southern blot analysis detected no new rearrangements demonstrating stable transgene integration ...


Identification And Characterization Of Proteins Expressed In The Nectar Of Ornamental Tobacco , Clay Jeremy Carter Jan 2002

Identification And Characterization Of Proteins Expressed In The Nectar Of Ornamental Tobacco , Clay Jeremy Carter

Retrospective Theses and Dissertations

A small set of proteins, termed Nectarins, are secreted into the nectar of ornamental tobacco (Nicotiana langsdorffii x Nicotiana sanderae). The most highly expressed protein, Nectarin I (29 kD monomer), was originally identified as a germin-like protein (GLP) of unknown function. This remarkably stable protein was later shown to possess manganese dependent superoxide dismutase activity. Hydrogen peroxide, the product of SOD activity, was found to accumulate in nectar at levels up to 4 mM. The promoter (1.2 kb) of the Nectarin I gene was fused to the reporter gene chloramphenicol acetyl transferase (CAT) and shown to be expressed in ...


Molecular Marker Analysis Of Seed Size In Soybean , Joseph Andrew Hoeck Jan 2002

Molecular Marker Analysis Of Seed Size In Soybean , Joseph Andrew Hoeck

Retrospective Theses and Dissertations

Seed size is an important attribute of soybean [Glycine max (L.) Merr.] for some food uses. The objectives of this study were to identify markers associated with quantitative trait loci for seed size (SSQTL), determine the influence of the environment on expression of the marker-SSQTL associations, and compare the efficiency of phenotypic selection and marker-assisted selection for the trait. Three small-seeded lines were crossed to a line or cultivar with normal seed size to form three two-parent populations. The parents of the populations were screened with 178 simple sequence repeat (SSR) markers to identify polymorphism. Population 1 (Pop 1) had ...


Enzyme Activities In Soils As Affected By Management Practices , Mine Ekenler Jan 2002

Enzyme Activities In Soils As Affected By Management Practices , Mine Ekenler

Retrospective Theses and Dissertations

Studies were undertaken to investigate the long-term effects of lime application and tillage systems (no-till, ridge-till, and chisel plow) on soil microbial biomass C (Cmic) and N (Nmic) and the activities of glycosidases (alpha- and beta-glucosidases, alpha- and beta-galactosidases and beta-glucosaminidase); phosphatases (acid and alkaline phosphatases and phosphodiesterase); amidohydrolases (L-asparaginase, L-glutaminase, amidase, urease, and L-aspartase); and arylamidase at their optimal pH values. With the exception of acid phosphatase, which was significantly but negatively correlated, all other enzyme activities were significantly and positively correlated with soil pH values at four sites in Iowa. Delta activity/Delta pH values showed that among ...


Backcross Introgression And Two-Stage Testing For Conversion Of Improved Tropical Germplasm To Temperate Environments , Freeman Callaway Whitehead Jan 2002

Backcross Introgression And Two-Stage Testing For Conversion Of Improved Tropical Germplasm To Temperate Environments , Freeman Callaway Whitehead

Retrospective Theses and Dissertations

The use of exotic maize (Zea mays L.) germplasm, particularly of tropical and subtropical adaptation, has been suggested to increase genetic variability and grain yield of maize breeding material in temperate environments. Lack of adaptation to temperate areas and photoperiod sensitivity may mask desirable traits and reduce breeding progress. The objectives of this study included two-stage evaluation and selection of segregating families in the central U.S. Corn Belt derived from the backcross introgression of previously improved tropical CIMMYT germplasm into adapted, elite U.S. Corn Belt germplasm. The U.S. Corn Belt heterotic patterns of Stiff Stalk and non-Stiff ...


Response To S1 Recurrent Selection And Estimation Of Genetic Parameters In Effective Population Sizes Of The Bs11 Maize Population , Kebede Mulatu Ponta Jan 2001

Response To S1 Recurrent Selection And Estimation Of Genetic Parameters In Effective Population Sizes Of The Bs11 Maize Population , Kebede Mulatu Ponta

Retrospective Theses and Dissertations

Recurrent selection is a cyclical breeding technique that has become popular in comprehensive maize improvement strategies. The magnitude of response in recurrent selection depends upon the modes of gene action and their frequencies in effective population sizes. We studied four effective population sizes with the objectives: (1) to estimate response to selection and inbreeding effects, (2) to partition the response to selection into that due to additive and dominance genetic components, and (3) to examine changes in the correlated traits. Four effective population sizes 5, 10, 20, and 30 were developed by S1-progeny selection in the BS11 maize population using ...


The 1dx5 High Molecular Weight Subunit Gene From Wheat In Transgenic Maize , Varaporn Sangtong Jan 2001

The 1dx5 High Molecular Weight Subunit Gene From Wheat In Transgenic Maize , Varaporn Sangtong

Retrospective Theses and Dissertations

We have developed a method for detecting a transgene and its protein product in maize endosperm that allows the kernel to be germinated after analysis. Our method involves first sampling the endosperm with a hand-held rotary grinder. This tissue is then serially extracted for phenotypic analysis by SDS-PAGE with visualization by total protein staining or immuno-blot detection and genotypic analysis by PCR reactions to detect the transgene. This method is useful for screening transgenic kernels in breeding experiments. We have produced transgenic maize plants containing a wheat Glu-1Dx5 gene encoding the high molecular weight glutenin subunit 1Dx5. Analysis by SDS-PAGE ...


Genetic Analysis Of Reproductive Traits In Soybean [Glycine Max (L) Merr] , I. Made Tasma Jan 2001

Genetic Analysis Of Reproductive Traits In Soybean [Glycine Max (L) Merr] , I. Made Tasma

Retrospective Theses and Dissertations

The objectives of this study were to: (1) estimate the number of genes controlling photoperiod insensitivity in soybean; (2) map quantitative trait loci controlling flowering time, maturity, and photoperiod insensitivity in soybean; (3) map homologous and cloned flowering time gene sequences in soybean; (4) correlate these sequences with maturity (E) loci by means of near isogenic lines (NILs). Three populations, two F 6:7 recombinant inbred lines of 101 and 100 progeny and an F2:4 G. max x G. soja population (60 progeny), were used. Forty-one NILs were also included. At least three genes were proposed to control photoperiod ...


Assessment Of Plant Introductions For Increasing The Genetic Variability Of Soybean Populations , James Mark Narvel Jan 1999

Assessment Of Plant Introductions For Increasing The Genetic Variability Of Soybean Populations , James Mark Narvel

Retrospective Theses and Dissertations

Plant introductions (PIs) may increase the genetic variability of soybean populations and lead to greater genetic gains from selection. Five soybean populations containing different percentages of PI parentage were developed at Iowa State University to evaluate the use of PIs for increasing genetic variability for seed yield in a recurrent selection program. The objective of this study was to evaluate the performance and genetic variability of the Cycle 4 (C4) populations of AP 10 (100 % PI), AP 11 (75 % PI), AP12 (50 % PI), AP13 (25 % PI), and AP14 (0 % PI) for agronomic traits and seed composition. Multiplexing technology for simple ...


Selection For Soybean Seed Yield With Molecular Markers , Joseph Richard Byrum Jan 1999

Selection For Soybean Seed Yield With Molecular Markers , Joseph Richard Byrum

Retrospective Theses and Dissertations

Molecular markers may facilitate the identification of and selection for quantitative trait loci (QTL) that control economically important traits. The objective of the study was to compare the efficiency of selection among soybean [Glycine max (L.) Merrill] lines for seed yield based on single replication progeny-row-yield tests (PRYT), molecular marker loci selected by pedigree analysis, and a combination of PRYT and molecular marker data. A total of 380 random F3-derived lines from three populations were evaluated in the PRYT at Ames, IA, in 1997 and were genotyped for simple sequence repeats (SSRs) that had been chosen by pedigree analysis for ...


Evaluation Of Recurrent Selection In Leaming And Midland Maize Populations , Marcelo Javier Carena Jan 1999

Evaluation Of Recurrent Selection In Leaming And Midland Maize Populations , Marcelo Javier Carena

Retrospective Theses and Dissertations

Rates of maize (Zea mays L.) yield improvement in the United States has been reduced during the 1990's. Double-cycle breeding in a few old inbred lines and limited germplasm evaluation and utilization are possible explanations. Only one heterotic pattern (Iowa Stiff Stalk Synthetic x Lancaster Sure Crop) is being widely exploited in U.S. dent maize breeding programs. Alternative U.S. heterotic patterns have been suggested, but they received limited attention and improvement. The objectives of this research were to evaluate inbred-progeny recurrent selection in Leaming (originated in Ohio), the oldest known U.S. open-pollinated variety, and Midland Yellow ...


Genetic Analysis Of Quantitative Trait Loci With The Early Generations Of An Elite, Single-Cross Maize Population , Dwi Asmono Jan 1998

Genetic Analysis Of Quantitative Trait Loci With The Early Generations Of An Elite, Single-Cross Maize Population , Dwi Asmono

Retrospective Theses and Dissertations

The first objective of this study was to detect QTLs affecting agronomically important traits in the F2 plants of an elite, single-cross of maize (Zea mays L.). The second objective was to compare QTL detection in the F2 and F2:3 generations. The third objective was to compare QTL detection in two samples of F2:3 lines derived from the same F2 population;Thirty-eight QTLs affecting five traits were identified in the F2 plants. The QTLs were associated with 6 to 43% of the phenotypic variation. QTLs explaining more than 40% of the variation were observed for plant height and ...


Mutational Analysis Of Aspergillus Awamori Glucoamylase Selectivity To Improve Glucose Yield , Hsuan-Liang Liu Jan 1998

Mutational Analysis Of Aspergillus Awamori Glucoamylase Selectivity To Improve Glucose Yield , Hsuan-Liang Liu

Retrospective Theses and Dissertations

Three single mutations, Lys108→Arg, Lys108→Met and Tyr312→Trp, and one insertional mutation, 322-314 Loop, in Aspergillus awamori glucoamylase were constructed and tested along with four previously constructed thermostable mutations: Asn20→Cys/Ala27→Cys (SS), Ser30→Pro, Gly137→Ala, and Ser436→Pro, and one previously made thermosensitive mutation, Ala27→Pro, for their selectivity by high-concentration glucose condensation and maltodextrin hydrolysis reactions. Lys108 is important in substrate binding during maltooligosaccharide hydrolysis. Both SS and 311-314 Loop mutant GAs successfully decrease isomaltose formation rate and thus increase peak glucose yield. Tyr312→Trp GA helps to form a tighter hydrogen bond network ...


Protein Engineering Of The Ph Dependence And Substrate Specificity Of Glucoamylase From Aspergillus Awamori , Tsuei-Yun Fang Jan 1997

Protein Engineering Of The Ph Dependence And Substrate Specificity Of Glucoamylase From Aspergillus Awamori , Tsuei-Yun Fang

Retrospective Theses and Dissertations

Glucoamylase (EC 3.2.1.3) (GA), an enzyme that catalyzes the release of [beta]-D-glucose from the nonreducing ends of starch and related oligo- and polysaccharides, is widely used in industry to produce high-glucose syrups. Site-directed mutagenesis was used to construct mutations to obtain mutant enzymes with industrially desired alterations in pH dependence and substrate specificity;An increased pH optimum for GA would be industrially desirable so that it could be used in process conditions more similar to that of other enzymatic steps in starch processing. Five mutations were designed to remove or weaken the hydrogen bond between Ser411 ...


The Role Of Domain E In The Activity Of Bacillus Macerans Cyclodextrin Glucanotransferase , Hai-Yin Chang Jan 1997

The Role Of Domain E In The Activity Of Bacillus Macerans Cyclodextrin Glucanotransferase , Hai-Yin Chang

Retrospective Theses and Dissertations

Cyclodextrin glucanotransferase (CGT) folds into five domains A, B, C, D and E. Domain E has the ability to bind starch and cyclodextrins (CDs) and is considered the starch-binding domain of CGT. The role of domain E in the catalysis of Bacillus macerans cyclodextrin glucanotransferase was investigated by constructing five CGT mutants. The truncated CGT (CGT[delta]E) mutant was constructed by deleting domain E, and the chimeric CGT (CGT-SBD) by replacing domain E with the starch-binding domain (SBD) of Aspergillus glucoamylase I. The modified CGT (CGT+6) was constructed by inserting a six-amino-acid pseudo linker between domains D and ...


Genetic Analysis Of Quantitative Trait Loci With Inbred And Hybrid Progeny Of Maize , David Frederick Austin Jan 1997

Genetic Analysis Of Quantitative Trait Loci With Inbred And Hybrid Progeny Of Maize , David Frederick Austin

Retrospective Theses and Dissertations

The first objective of this study was to compare quantitative trait loci (QTL) detection in two climatically diverse environments in a population of F6:7 lines of an elite maize (Zea mays L.) single-cross. The second objective was to detect QTL for general (GCA) and specific (SCA) combining ability effects in hybrid progeny of F2:3 and F6:8 lines from the same population. Evaluations of both inbred per se and hybrid progeny from the same population enabled comparisons between QTL controlling the two progeny types;The results from the F6:7 inbred progeny evaluations suggest that QTL detection can ...


Genetic And Biochemical Analysis Of Aspergillus Awamori Glucoamylase Thermostability , Martin John Allen Jan 1997

Genetic And Biochemical Analysis Of Aspergillus Awamori Glucoamylase Thermostability , Martin John Allen

Retrospective Theses and Dissertations

Aspergillus awamori glucoamylase (GA) is an enzyme involved in industrial corn starch processing. Genetic and biochemical approaches were used to study the mechanisms governing GA thermostability. Three proline substitution (Xaa → Pro) mutations were constructed that were predicted to increase the enzyme's stability by decreasing its conformational entropy of unfolding. When expressed in Saccharomyces cerevisiae Ser30 → Pro increased, Asp345 → Pro did not alter and Glu408 → Pro greatly decreased GA stability as measured by resistance to irreversible thermoinactivation relative to the wild-type enzyme. The Ser30 → Pro mutation was combined with other previously identified stabilizing mutations to examine whether combining such mutations ...


Molecular Marker Analysis Of Iron Efficiency In Soybean (Glycine Max (L.) Merr.) , Shun-Fu Lin Jan 1996

Molecular Marker Analysis Of Iron Efficiency In Soybean (Glycine Max (L.) Merr.) , Shun-Fu Lin

Retrospective Theses and Dissertations

The objectives of the studies were to map genes affecting iron deficiency chlorosis in soybean, to test the hypothesis that two genetic mechanisms control iron deficiency chlorosis in soybean, and to determine the effectiveness of nutrient solution evaluation for iron deficiency chlorosis in soybean. Chlorosis symptoms of one hundred and twenty F2:4 lines from a Pride B216 x A15 population, and 92 F2:4 lines from an Anoka x A7 population grown in a field of calcareous soil in 1993 and 1994 were evaluated by visual scores and spectrometric chlorophyll determinations. Each population also was evaluated separately with two ...


The Relationship Between The Calpain Enzyme System And The Postmortem Degradation Of Selected Myofibrillar Proteins , Elisabeth Jane Huff Lonergan Jan 1995

The Relationship Between The Calpain Enzyme System And The Postmortem Degradation Of Selected Myofibrillar Proteins , Elisabeth Jane Huff Lonergan

Retrospective Theses and Dissertations

The protease [mu]-calpain degrades the myofibrillar proteins titin, nebulin, filamin, desmin and troponin-T. Titin and nebulin have been reported to be affected by sample preparation. This study showed that there was little difference in the rate of degradation of the intact forms due to sample preparation (whole muscle preparations vs. purified myofibrils). The postmortem degradation of titin, nebulin, filamin, desmin, and troponin-T was monitored using SDS-PAGE and Western blotting techniques at 0, 1, 3, 7, 14, 28, and 56 days postmortem. Postmortem aged samples with lower shear force values exhibited faster degradation of the five myofibrillar proteins. Similar degradation ...


Characterization And Application Of Porcine Liver Aldehyde Oxidase In The Removal Of Off-Flavors From Soy Proteins , Peeyush Maheshwari Jan 1995

Characterization And Application Of Porcine Liver Aldehyde Oxidase In The Removal Of Off-Flavors From Soy Proteins , Peeyush Maheshwari

Retrospective Theses and Dissertations

Two enzyme forms (PAO-I and PAO-II) of porcine liver aldehyde oxidase (aldehyde: oxygen oxidoreductase, EC 1.2.3.1) were purified to homogeneity using affinity chromatography. The heat treatment and ammonium sulfate fractionation steps resulted only in a partial purification. Both enzyme forms, PAO-I and PAO-II, have similar pIs of 5.8 and molecular weight of 262,000 and 255,000 daltons, respectively;The two enzyme forms exhibited different substrate specificities. Compared to PAO-II, PAO-I showed higher affinity for the medium-chain aldehydes (pentanal and hexanal) which are mainly responsible for the greeny and beany off-flavor of soybean products. The PAO-I ...


Sequence Variation Characteristics Of D-Loop, Rrna, Trna, And Polypeptide Coding Region Of Bovine Mitochondrial Dna , Jianming Wu Jan 1995

Sequence Variation Characteristics Of D-Loop, Rrna, Trna, And Polypeptide Coding Region Of Bovine Mitochondrial Dna , Jianming Wu

Retrospective Theses and Dissertations

By cloning and sequencing the mtDNA of cows from different maternal lineages, it was found that multiple heteroplasmic mtDNA states within the D-loop and rRNA genes of mtDNA existed extensively in Holstein cattle. Meanwhile, the nature and transmission of mtDNA were investigated. The mtDNA population in a specific animal was found to be a mixture of different genotypes. Because heteroplasmy was observed frequently and seemingly is persistent, selected amplification of specific mtDNA molecules may not be a part of mtDNA inheritance. At same time, four hypervariable sites were located at nt 169, 216, and 1594 between nt 352 to 364 ...


Effects Of Ear Developmental Temperature On Fine Structure Of Maize Starch , Ting-Jang Lu Jan 1995

Effects Of Ear Developmental Temperature On Fine Structure Of Maize Starch , Ting-Jang Lu

Retrospective Theses and Dissertations

Two genetically unrelated normal dent maize inbreds, ICI63 and ICI92, with different heterotic backgrounds were used for studying environmental temperature effects on grain yield and quality. These two maize inbreds are used in commercially available hybrids and are proprietary to ICI Seeds. The maize inbreds were grown in a greenhouse to control the growing condition of the plants. After 14 days post-pollination, the ears were wrapped in temperature control devices set at 25 or 35∘ C during the grain-filling period. Grain yield, kernel weight, and kernel density were less for ears developing at 35∘ C than for those at 25 ...