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Yuxi Gong,1 Haitao Yan,2 Yefan Yang,1 Boya Zhai,1 Zhendong Huang,1 Zhihong Zhang1 1Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, People’s Republic of China; 2Department of Interventional Radiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, People’s Republic of ChinaCorrespondence: Zhihong Zhang, Department of Pathology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu Province, 210029, People’s Republic of China, Tel/Fax +86-25-68303709, Email zhangzh@njmu.edu.cnPurpose: To explore recurrence-risk factors of diffuse large B cell lymphoma (DLBCL) and construct a risk nomogram for predicting recurrence.Patients and Methods: A retrospective analysis was performed on 228 DLBCL patients who achieved complete remission after R-CHOP treatment between January 2015 and December 2019. Univariate and multivariate analyses were applied to identify recurrence-related risk factors from the pretreatment evaluation factors covering patients’ demographic characteristics, clinical manifestations, serological indicators, pathological and immunohistochemical results. A nomogram was developed based on the above results and validated by the concordance index (C-index), the receiver operating characteristic (ROC) curve, and the calibration curve.Results: The training and validation cohorts consisted of 160 and 68 patients (randomized by 7:3). Of the whole cohort, 50 of 228 (21.9%) cases recurred during follow-up. Three recurrence-risk factors including BCL2 expression (P = 0.027), CD10 expression (P = 0.021), LDH level (P = 0.004) were identified from multivariate analysis and entered the final nomogram. The C-index of the nomogram was 0.815 in training cohort and 0.797 in the validation cohort, higher than that of IPI system (0.699) and NCCN-IPI system (0.709). And the 1-year, 2-year, 3-year, and 4-year areas under ROC (AUC) were 0.812, 0.850, 0.837, and 0.801, respectively. The calibration curves also showed a good discrimination capability and accuracy.Conclusion: The novel nomogram incorporating the three independent risk factors (BCL2 expression, CD10 expression and LDH level) provided a valuable tool for predicting DLBCL recurrence.Keywords: diffuse large B cell lymphoma, DLBCL, recurrence, nomogram, risk factors

Purposes: To explore recurrence-risk factors of diffuse large B cell lymphoma (DLBCL) and construct a risk nomogram for predicting recurrence and risk stratification.Materials and Methods: A retrospective analysis was performed on 228 DLBCL patients who achieved complete remission after initial treatment between January 2015 and December 2019. Univariate and multivariate analyses were applied to identify recurrence-related risk factors from the pretreatment evaluation factors covering patients’ demographic characteristics, clinical manifestations, serological indicators, pathological and immunohistochemical results. A nomogram was developed based on the above results and validated by the concordance index (C-index), the receiver operating characteristic (ROC) curve, and the calibration curve. Results: Fifty of 228(21.9%) cases recurred during follow-up. Three recurrence-risk factors including BCL2 expression (P=0.013), Ann Arbor stage (P=0.011), LDH level (P=0.038) were identified from multivariate analysis and entered the final nomogram “ABL-nomogram”. The C-index of the ABL-nomogram was 0.808, higher than that of IPI system (0.717) and NCCN-IPI system (0.714). And the 1-year, 2-year, 3-year, and 4-year areas under ROC(AUC) were 0.851, 0.859, 0.843, and 0.791, respectively. The calibration curves also showed a good discrimination capability and accuracy. DLBCL could be divided into four subgroups (G1, G2, G3, G4) with significant differences in recurrence risk based on the total points calculated from ABL-nomogram. Conclusions: ABL-nomogram incorporating the three independent risk factors (BCL2 expression, Ann Arbor stage and LDH level) for DLBCL recurrence, had a better ability to assist risk stratification and identify DLBCL patients with high recurrence risk than IPI system or NCCN-IPI system.

Background Monomorphic epitheliotropic T-cell lymphoma (MEITL) is an aggressive non-Hodgkin lymphoma with a high fatality rate. This study was aimed to explore the clinicopathological and molecular genetic features of MEITL in the Chinese population. Methods A retrospective analysis was performed based on the clinical manifestations and pathological features of 20 Chinese MEITL. 9 cases with paired diseased-normal tissues were also analyzed for molecular information by whole-exome sequencing. Results There were 14 men and 6 women with a median age of 58.5 (28-81) years. 17(17/20) lesions were located in the jejunum or ileum; 13(13/20) cases had ulcers or perforations. Microscopically, except for 1(1/20) case of pleomorphic cells, the monomorphic, middle-sized tumor cells infiltrating into the intestinal epithelial and peripheral intestinal mucosa recess could be seen in the other 19 cases. Immunohistochemistry showed that most of the tumor cells in MEITL were positive for CD3(20/20), CD8(17/20), CD43(19/20), and CD56(15/20), but negative for CD5(20/20). The most frequently mutated genes of these Chinese cases were STAT5B (4/9) and TP53 (4/9), not SETD2(2/9). JAK3 mutations (3/9) were also detected with a high mutated frequency. We demonstrated that mutations of JAK-STAT pathway-related genes and the amplification of Chromosome 9q appeared at the same time in most cases(5/9). Conclusions The clinicopathological features were consistent with that in previous western studies, but a special case with pleomorphic cells was found in this study. The co-occurrence of JAK-STAT pathway-related gene mutations and the amplification of Chr9q is a molecular feature of MEITL.

The criteria of engineering education accreditation are student-centered, outcome-based, and continuous improvement focused. The accreditation focuses on developing students' ability to solve complex engineering problems. In this context, as one of the core courses of computer related undergraduate majors, the principle of computer organization course transforms the ability cultivation requirement of engineering education accreditation into cultivation of system capability. In order to achieve the cultivation requirement, a construction scheme of online learning platform of the course is proposed. The scheme includes the construction of high-quality course resources, excellent case base, and analysis of students' learning behavior. The implementation of the scheme provides a foundation platform for students to improve problem analysis ability, to form accomplishment on engineering design and using specialized knowledge to solve practical problems, and to establish the sense of life-long learning and self-learning. It also provides the data support and breakthrough point for reform in teaching and learning, to ensure that the course construction keeps student-centered, outcome-based, and continuous improvement focused.

Polymerase chain reaction (PCR) is a new technique for rapid amplification of specific DNA fragments. Some mechanisms of bio-macromolecule interaction in PCR reactions appear as a cluster during DNA amplification. There are many possible dynamic processes. Aiming at the problem that the DNA amplification process is difficult to be completely characterized by existing experimental methods, the mathematical model of DNA amplification process is proposed and a band describing the PCR process is established and a nonlinear hybrid system with parameters is given. Experiments are carried out and the results show that the proposed method is robust.

As traditional Canny operator is manually determined in the threshold for edge detection, we presented an improved Canny algorithm based on adaptive two-dimensional Otsu and Newton Iterative. The algorithm bases on gray distribution characteristics of underwater suspended particles, it uses inter-class variance (Otsu) adaptive algorithm to determine the optimal threshold to connect and trace edge. To reduce computational complexity and traversal cycle, improve real-time capability in Otsu, we employ the Newton iteration method to quickly converge to the optimal high and low threshold of Canny Algorithm. The experimental results show that it can solve the contradiction between the noise filtering and edge maintenance. Therefore, it has strong robustness and adaptability.

The region (101-112) of C1B domain in PKCγ plays a crucial role in the activation of the enzyme and subsequent gap junction inhibition. Substitution studies on peptides correlating to the C1B region show that a flexible structure and ability to be phosphorylated on serine 109 are critical for this purpose.

In response to wounding or infection, insects produce a battery of antimicrobial peptides (AMPs) and other defense molecules to kill the invading pathogens. To study their structures, functions, and transcriptional regulation, we synthesized Manduca sexta moricin, a 42-residue peptide (GKIPVKAIKQAGKVIGKGLRAINIAGTTHDVVSFFRPKKKKH, 4539 Da). The compound exhibited potent antimicrobial activities against a broad spectrum of Gram-positive and Gram-negative bacteria with a minimum inhibitory concentration of 1.4 µM. The mRNA levels of M. sexta moricin increased substantially in fat body and hemocytes after the larvae were challenged with bacterial cells. We determined the solution structure of this AMP by two-dimensional 1H1H -nuclear magnetic resonance spectroscopy. The tertiary structure is composed of an eight-turn α-helix spanning almost the entire peptide. Insights of relationships between the structure and function are also presented. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.

Cationic antimicrobial peptides are naturally occurring antibiotics that are actively being explored as a new class of anti-infective agents. We recently identified three cathelicidin antimicrobial peptides from chicken, which have potent and broad-spectrum antibacterial activities in vitro (Xiao Y, Cai Y, Bommineni YR, Fernando SC, Prakash O, Gilliland SE & Zhang G (2006) J Biol Chem281, 2858-2867). Here we report that fowlicidin-1 mainly adopts an alpha-helical conformation with a slight kink induced by glycine close to the center, in addition to a short flexible unstructured region near the N terminus. To gain further insight into the structural requirements for function, a series of truncation and substitution mutants of fowlicidin-1 were synthesized and tested separately for their antibacterial, cytolytic and lipopolysaccharide (LPS)-binding activities. The short C-terminal helical segment after the kink, consisting of a stretch of eight amino acids (residues 16-23), was shown to be critically involved in all three functions, suggesting that this region may be required for the peptide to interact with LPS and lipid membranes and to permeabilize both prokaryotic and eukaryotic cells. We also identified a second segment, comprising three amino acids (residues 5-7) in the N-terminal flexible region, that participates in LPS binding and cytotoxicity but is less important in bacterial killing. The fowlicidin-1 analog, with deletion of the second N-terminal segment (residues 5-7), was found to retain substantial antibacterial potency with a significant reduction in cytotoxicity. Such a peptide analog may have considerable potential for development as an anti-infective agent.

The side chains of Arg 50 and Arg 52 at positions P6' and P8', respectively, anchor the binding loop to the protein scaffold by means of hydrogen bonds in Cucurbita maximatrypsin inhibitor-V (CMTI- V), a potato I family member. Here, we have investigated the relative contributions of Arg 50 and Arg 52 to the binding-loop flexibility and stability by determining changes in structure, dynamics, and proteolytic stability as a consequence of individually mutating them into an alanine. We have compared chemical shift assignments of main-chain hydrogens and nitrogens, and 1 H- 1 H interresidue nuclear Overhauser effects (NOEs) for the two mutants with those of the wild-type protein. We have also measured NMR longitudinal and transverse relaxation rates and 15 N- 1 H NOE enhancements for all backbone and side- chain NH groups and calculated the model-free parameters for R50A-rCMTI-V and R52A-rCMTI-V. The three-dimensional structures and backbone dynamics of the protein scaffold region remain very similar for both mutants, relative to the wild-type protein. The flexibility of the binding loop is increased in both R50A- and R52A-rCMTI-V. In R52A-rCMTI-V, the mean generalized order parameter ( )o f the P6-P1 residues of the binding loop (39-44) decreases to 0.68 ( 0.02 from 0.76 ( 0.04 observed for the wild-type protein. However, in R50A-rCMTI-V, the flexibility of the whole binding loop increases, especially that of the P1'-P3' residues (45-47), whose value drops dramatically to 0.35 ( 0.03 from 0.68 ( 0.03 determined for rCMTI-V. More strikingly, S 2 values of side-chain NHs reveal that, in the R50A mutant, removal of the R50 hydrogen bond results in the loss of the R52 hydrogen bond too, whereas in R52A, the R50 hydrogen bond remains unaffected. Kinetic data on trypsin-catalyzed hydrolysis of the reactive-site peptide bond (P 1-P1') suggest that the activation free energy barrier of the reaction at 25 °C is reduced by 2.1 kcal/mol for R50A-rCMTI-V and by 1.5 kcal/mol for R52A-rCMTI-V, relative to rCMTI-V. Collectively, the results suggest that although both the P 6' and P8' anchors are required for optimal inhibitor function and stability in the potato I family, the former is essential for the existence of the latter and has greater influence on the binding-loop structure, dynamics, and stability.

Serine proteinase protein inhibitors follow the standard mechanism of inhibition (Laskowski M Jr, Kato I, 1980, Annu Rev Biochem 49:593-626), whereby an enzyme-catalyzed equilibrium between intact (I) and reactive-site hydrolyzed inhibitor (I*) is reached. The hydrolysis constant, Khyd, is defined as [I*]/[I]. Here, we explore the role of internal dynamics in the resynthesis of the scissile bond by comparing the internal mobility data of intact and cleaved inhibitors belonging to two different families. The inhibitors studied are recombinant Cucurbita maxima trypsin inhibitor III (rCMTI-III; Mr 3 kDa) of the squash family and rCMTI-V (Mr approximately 7 kDa) of the potato I family. These two inhibitors have different binding loop-scaffold interactions and different Khyd values--2.4 (CMTI-III) and 9 (CMTI-V)--at 25 degrees C. The reactive-site peptide bond (P1-P1') is that between Arg5 and Ile6 in CMTI-III, and that between Lys44 and Asp45 in CMTI-V. The order parameters (S2) of backbone NHs of uniformly 15N-labeled rCMTI-III and rCMTI-III* were determined from measurements of 15N spin-lattice and spin-spin relaxation rates, and [1H]-15N steady-state heteronuclear Overhauser effects, using the model-free formalism, and compared with the data reported previously for rCMTI-V and rCMTI-V*. The backbones of rCMTI-III [(S2) = 0.71] and rCMTI-III* [(S2) = 0.63] are more flexible than those of rCMTI-V [(S2) = 0.83] and rCMTI-V* [(S2) = 0.85]. The binding loop residues, P4-P1, in the two proteins show the following average order parameters: 0.57 (rCMTI-III) and 0.44 (rCMTI-III*); 0.70 (rCMTI-V) and 0.40 (rCMTI-V*). The P1'-P4' residues, on the other hand, are associated with (S2) values of 0.56 (rCMTI-III) and 0.47 (rCMTI-III*); and 0.73 (rCMTI-V) and 0.83 (rCMTI-V*). The newly formed C-terminal (Pn residues) gains a smaller magnitude of flexibility in rCMTI-III* due to the Cys3-Cys20 crosslink. In contrast, the newly formed N-terminal (Pn' residues) becomes more flexible only in rCMTI-III*, most likely due to lack of an interaction between the P1' residue and the scaffold in rCMTI-III. Thus, diminished flexibility gain of the Pn residues and, surprisingly, increased flexibility of the Pn' residues seem to facilitate the resynthesis of the P1-P1' bond, leading to a lower Khyd value.

Reactive-site (Lys44-Asp45 peptide bond) hydrolyzed Cucurbita maxima trypsin inhibitor-V (CMTI-V*) was prepared and characterized: In comparison to the intact form, CMTI-V* exhibited markedly reduced inhibitory properties and binding affinities toward trypsin and human blood coagulation factor XIIa. The equilibrium constant of trypsin-catalyzed hydrolysis, Khyd, defined as [CMTI-V*]/[CMTI-V], was measured to be approximately 9.4 at 25 degrees C (delta G degrees = -1.3 kcal.mol-1). From the temperature dependence of delta G degrees, the following thermodynamic parameters were estimated: delta H degrees = 1.6 kcal.mol-1 and delta S degrees = 9.8 eu. In order to understand the functional and thermodynamic differences between the two forms, the three-dimensional solution structure of CMTI-V* was determined by a combined approach of NMR, distance geometry, and simulated annealing methods. Thus, following sequence-specific and stereospecific resonance assignments, including those of beta-, gamma-, delta-, and epsilon-hydrogens and valine methyl hydrogens, 809 interhydrogen distances and 123 dihedral angle constraints were determined, resulting in the computation and energy-minimization of 20 structures for CMTI-V*. The average root mean squared deviation in position for equivalent atoms between the 20 individual structures and the mean structure obtained by averaging their coordinates is 0.67 +/- 0.15 A for the main chain atoms and 1.19 +/- 0.23 A for all the non-hydrogen atoms of residues 5-40 and residues 48-67.(ABSTRACT TRUNCATED AT 250 WORDS)

Stereospecific assignments are made for gamma- and delta-methylene hydrogens in a protein by means of estimation of vicinal 1H-1H spin-spin coupling constants from a short-mixing-time TOCSY experiment. 3J alpha beta coupling constants, as measured from a P.E. COSY map, are shown to be well correlated with alpha-beta cross-peak intensities of a short-mixing-time (10 ms) TOCSY map. The procedure is illustrated by application to a trypsin-inhibitor protein (M(r) approximately 7 Kd). Thus, gamma-methylene hydrogens of isoleucine residues have been stereospecifically assigned on the basis of 3J beta gamma 1H-1H coupling patterns and intraresidue cross-peak intensities in a NOESY map; gamma-hydrogens of other residues, such as lysine and arginine, have been stereospecifically assigned solely on the basis of cross-peak intensity patterns resulting from coupling of two beta-hydrogens to two gamma-hydrogens, and in conjunction with stereospecific assignments of beta-methylene hydrogens. However, intraresidue NOE intensities are needed if one or two pairs of coupling constants cannot be estimated because of cross peaks either overlapping or occurring proximal to the diagonal. The delta-methylene hydrogens have been stereospecifically assigned on the basis of coupling between two gamma-hydrogens and two delta-hydrogens, in combination with stereospecific assignments of gamma-hydrogens. Stereospecific assignments of side chains should contribute to the overall precision and accuracy of NMR-determined three-dimensional solution structures of proteins.

For the phonemon for over fitting in the current recommendation system, put forward using the fuzzy scatter difference to the recommendation algorithm. The algorithm avoids the robustness in original collaborative filtering recommendation system for only calculating the user's similarities. The Experimental results show that the system has good accuracy and efficiency of the recommendation under the three indexes of MAE, RMSE and correlation, especially in the case of sparse initial data.

Put the predicting query performance(PQP) into the query fusion and construct a new adaptive information retrieval system(QAAIR) based on performance analysis in the base of analyzing the method of PQP for IR system and expound the main technique. The experiment adopted testing data of TREC web track show the method can improve the effectiveness of query and overcome the robust of information retrieval.

In order to quickly and accurately using mass information in the Deep Web database. According to the characteristics of the Deep Web: large-scale, dynamic and heterogeneity, Put forward one new query fusion method based on the prediction query performance (PQP) for the first time. And put forward a new pseudo prediction query performance method. Adopted testing data of UIUC, The experiment show the method can improve the effectiveness of query.

Analyzing the present situation of personalized recommendation system. Point out the limitation of similarity based on voting, and the disadvantage of the strict matching in calculating similarity. Put forward a new personalized recommendation method based on the statistics of item. Adopt the cloud model to calculate the similarity instead of traditional strict matching of cosine method. The experiments show that the system has better performance.

In order to quickly and accurately using mass information in the Deep Web database. According to the characteristics of the Deep Web: large-scale, dynamic and heterogeneity, One new query method was put forward based on the document divergence for the first time. The experiment adopted testing data of TREC show the method can avoid the repeat of query document in effect, especially for a great deal of documents returned from the deep web database. The method improves the effectiveness of query.

A protein inhibitor (CMTI-V; Mr 7106) of trypsin and activated Hageman factor (Factor XIIa), a serine protease involved in blood coagulation, has been isolated for the first time from pumpkin (Cucurbita maxima) seeds by means of trypsin-affinity chromatography and reverse phase high performance liquid chromatography (HPLC). The dissociation constants of the inhibitor complexes with trypsin and Factor XIIa have been determined to be 1.6 × 10−8 and 4.1 × 10−8 M, respectively. The primary structure of CMTI-V is reported. The protein has 68 amino acid residues and one disulfide bridge and shows a high level of sequence homology to the Potato I inhibitor family. Furthermore, its amino terminus consists of an N-acetylates Ser. The reactive site has been established to be the peptide bond between Lys44-Asp45. The modified inhibitor which has the reactive site peptide bond hydrolyzed inhibits trypsin but not the Hageman factor.

A number of channel-forming peptides derived from the second transmembrane (TM) segment (M2) of the glycine receptor alpha(1) subunit (M2GlyR), including the 22-residue sequence NK(4)-M2GlyR p22 wild type (WT) (KKKKPARVGLGITTVLTMTTQS), induce anion permeation across epithelial cell monolayers. In vitro assays suggest that this peptide or related sequences might function as a candidate for ion channel replacement therapy in treating channelopathies such as cystic fibrosis (CF). The wild-type sequence forms soluble associations in water that diminish its efficacy. Introduction of a single substitution S22W at the C-terminus, NK(4)-M2GlyR p22 S22W, eliminates the formation of higher molecular weight associations in solution. The S22W peptide also reduces the concentration of peptide required for half-maximal anion transport induced across Madin-Darby canine kidney cells (MDCK) monolayers. A combination of 2D double quantum filtered correlation spectroscopy (DQF-COSY), total correlation spectroscopy (TOCSY), nuclear Overhauser effect spectroscopy (NOESY), and rotating frame nuclear Overhauser effect spectroscopy (ROESY) data were recorded for both the associating WT and nonassociating S22W peptides and used to compare the primary structures and to assign the secondary structures. High-resolution structural studies were recorded in the solvent system (40% 2,2,2-Trifluoroethanol (TFE)/water), which gave the largest structural difference between the two peptides. Nuclear Overhauser effect crosspeak intensity provided interproton distances and the torsion angles were measured by spin-spin coupling constants. These constraints were put into the DYANA modeling program to generate a group of structures. These studies yielded energy-minimized structures for this mixed solvent environment. Structure for both peptides is confined to the 15-residue transmembrane segments. The energy-minimized structure for the WT peptide shows a partially helical extended structure. The S22W peptide adopts a bent conformation forming a hydrophobic pocket by hydrophobic interactions.

The solution structure of recombinant Cucurbita maxima trypsin inhibitor-V (rCMTI-V), whose N-terminal is unacetylated and carries an extra glycine residue, was determined by means of two-dimensional (2D) homo and 3D hetero NMR experiments in combination with a distance geometry and simulated annealing algorithm. A total of 927 interproton distances and 123 torsion angle constraints were utilized to generate 18 structures. The root mean squared deviation (RMSD) of the mean structure is 0.53 A for main-chain atoms and 0.95 A for all the non-hydrogen atoms of residues 3-40 and 49-67. The average structure of rCMTI-V is found to be almost the same as that of the native protein [Cai, M., Gong, Y., Kao, J.-L.,Krishnamoorthi, R. (1995) Biochemistry 34, 5201-5211]. The backbone dynamics of uniformly 15N-labeled rCMTI-V were characterized by 2D 1H-15N NMR methods. 15N spin-lattice and spin-spin relaxation rate constants (R1 and R2, respectively) and [1H]-15N steady-state heteronuclear Overhauser effect enhancements were measured for the peptide NH units and, using the model-free formalism [Lipari, G.,Szabo, A. (1982) J. Am. Chem. Soc. 104, 4546-4559, 4559-4570], the following parameters were determined: overall tumbling correlation time for the protein molecule (tau m), generalized order parameters for the individual N-H vectors (S2), effective correlation times for their internal motions (tau e), and terms to account for motions on a slower time scale (second) due to chemical exchange and/or conformational averaging (R(ex)). Most of the backbone NH groups of rCMTI-V are found to be highly constrained ((S2) = 0.83) with the exception of those in the binding loop (residues 41-48, (S2) = 0.71) and the N-terminal region ((S2) = 0.73). Main-chain atoms in these regions show large RMSD values in the average NMR structure. Residues involved in turns also appear to have more mobility ((S2) = 0.80). Dynamical properties of rCMTI-V were compared with those of two other inhibitors of the potato I family--eglin c [Peng, J. W.,Wagner, G. (1992) Biochemistry 31, 8571-8586] and barley chymotrypsin inhibitor 2 [CI-2; Shaw, G. L., Davis, B., Keeler, J.,Fersht, A. R. (1995) Biochemistry 34, 2225-2233]. The Cys3-Cys48 linkage found only in rCMTI-V appears to somewhat reduce the N-terminal flexibility; likewise, the C-terminal of rCMTI-V, being part of a beta-sheet, appears to be more rigid.

The solution structure of Cucurbita maxima trypsin inhibitor-V (CMTI-V), which is also a specific inhibitor of the blood coagulation protein, factor XIIa, was determined by 1H NMR spectroscopy in combination with a distance-geometry and simulated annealing algorithm. Sequence-specific resonance assignments were made for all the main-chain and most of the side-chain hydrogens. Stereospecific assignments were also made for some of the beta-, gamma-, delta-, and epsilon-hydrogens and valine methyl hydrogens. The ring conformations of all six prolines in the inhibitor were determined on the basis of 1H-1H vicinal coupling constant patterns; most of the proline ring hydrogens were stereospecifically assigned on the basis of vicinal coupling constant and intraresidue nuclear Overhauser effect (NOE) patterns. Distance constraints were determined on the basis of NOEs between pairs of hydrogens. Dihedral angle constraints were determined from estimates of scalar coupling constants and intraresidue NOEs. On the basis of 727 interproton distance and 111 torsion angle constraints, which included backbone phi angles and side-chain chi 1, chi 2, chi 3, and chi 4 angles, 22 structures were calculated by a distance geometry algorithm and refined by energy minimization and simulated annealing methods. Both main-chain and side-chain atoms are well-defined, except for a loop region, two terminal residues, and some side-chain atoms located on the molecular surface. The average root mean squared deviation in the position for equivalent atoms between the 22 individual structures and the mean structure obtained by averaging their coordinates is 0.58 +/- 0.06 A for the main-chain atoms and 1.01 +/- 0.07 A for all the non-hydrogen atoms of residues 3-40 and 49-67. These structures were compared to the X-ray crystallographic structure of another protein of the same inhibitor family-chymotrypsin inhibitor-2 from barley seeds [CI-2; McPhalen, C. A., & James, M. N. G. (1987) Biochemistry 26, 261-269]. The main-chain folding patterns are highly similar for the two proteins, which possess 62% sequence differences. However, major differences are noted in the N- and C-terminal segments, which may be due to the presence of a disulfide bridge in CMTI-V, but not in CI-2.